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Recycling of contaminated waste glass in ultra-high performance concrete: Impurities impact
... Owing to this, various researchers, recommended the utilization of recycled coarse aggregate [22][23][24][25][26][27][28][29][30][31][32][33], steel slag aggregate [34][35][36][37][38][39], waste glass aggregates [40][41][42][43][44][45][46], ceramic waste aggregates [47][48][49][50], waste brick aggregate [51][52][53][54][55][56], E-waste aggregate [57][58][59][60], oil palm shell aggregate [61][62][63], coconut shell aggregate [64][65][66][67][68][69], Expanded Polystyrene aggregate [70][71][72][73][74][75][76], sawdust ash [77], waste rubber tire aggregate [78][79][80][81][82][83][84], and lightweight aggregates [85][86][87][88][89][90], as a substitution material of natural aggregate. ...
Traditional waste management faces significant environmental, social, and economic
challenges, while concrete’s high resource consumption highlights the need for improved, low�density alternatives. Consequently, lightweight concrete (LWC) has emerged as a favored
solution. Recent interest in using pumice aggregate in concrete arises from its advantageous
properties, such as low unit weight, which enables the construction of lighter buildings and
reduces the load on structural elements. This study aimed to create lightweight, sustainable
concrete using underutilized waste pumice aggregate (WPA). Concrete specimens with waste
pumice aggregate ratios of 20%, 40%, 60%, 80%, and 100% were analyzed at 7 and 28 days,
with results contrasted against the virgin sample. The testing protocol encompassed detailed
laboratory evaluations of concrete properties, including workability, density, strength, impact
energy, ultrasonic velocity, water absorption, and cost analysis. Experimental results indicated
that the inclusion of Waste pumice aggregate as a lightweight aggregate in concrete, in contrast
to conventional aggregates, results in reduced workability, density, and strength metrics, as
well as heightened water absorption, diminished impact energy, and lower ultrasonic pulse
velocity. Sustainable or green concrete from M-20 to M-60 along strength ≥17 MPa is for load�bearing applications, while M-80 and M-100 whose strength is <17 MPa are for non-load�bearing uses.
... Research has thus shown that fillers exhibit some physical-chemical activity, which promotes the acceleration of clinker hydration and contributes to a pozzolanic reaction (Zhu & Gibbs, 2005;Diederich et al., 2013). The valorization of glass waste in the field of materials could be an interesting ecological and economical solution (Zhao et al., 2024). Glass powder (GP) has now become an effective addition to the field of building materials. ...
In Algeria, glass waste is underutilized in the industrial sector; however, its potential use in civil engineering offers a significant ecological and economic opportunity. This approach could be a solution to eliminate illegal dumping sites, reduce pollution, and provide a new source of sustainable construction materials. In this context, this research aimed to produce self-compacting concrete (SCC) mixtures using recycled glass powder as a replacement for limestone filler. This research presents an experimental study investigating the impact of glass powder waste as a replacement for the traditionally used limestone filler in self-compacting concrete. To investigate the workability and compressive strength of the SCC studied, eleven concrete mixtures were prepared with varying substitution rates of limestone filler (0%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%) with powder glass. The use of powdered glass waste has beneficial effects, as the pozzolanic reaction generates an additional amount of hydrated calcium silicates. The results of the investigation showed an increase in compressive strength compared to the control concrete specimen (without glass powder). The best results were observed when incorporation ranged between 10% and 50%, with the optimal level being 30%, resulting in an 8.47% strength gain. This study contributes to the valorization of glass powder as a substitute for limestone filler. The results demonstrate positive effects on both fresh and hardened characteristics when using glass powder in proportions ranging from 10% to 50% of the filler mass.
An innovative method is proposed in this study that combines long sequence precision prediction model with experiments to study how early hydration affects ultra‐low water‐binder ratio cementitious composite (ULWBRCC) properties. To be specific, by using heat release and degree of hydration as variables and introducing various temporal models to analyze the early hydration process, the micro‐ and macroscopic properties of specimens at different ages are assessed in detail. The obtained results can be summarized as follows: The long‐sequence accurate time series model can predict the earliest hydration process of underwater ULWBRCC, and the predicted late‐stage hydration pattern matches the experimental results. The underwater environment optimizes ULWBRCC's hydration process and increases its early compressive strength by 19.6%. The hydration of ULWBRCC is predicted using a time series model in the paper, filling the gap of uncertainty in the earliest performance of underwater rapid repair cement‐based composite materials, and the MSE of the Informer is improved by 92.88% compared with other models.
Here, the intrinsic driving mechanisms of autogenous shrinkage for Ultra-High Performance Concrete (UHPC) incorporating porous internal curing (IC) medium are detailly investigated, including characterization and monitoring of UHPC hydration kinetics, internal relative humidity (IRH) and internal temperature (IT) fields. The results show that the autogenous shrinkage evolution of UHPC prepared with pre-wet porous fine aggregate (PFA) undergoes multiple stages. The potential expansion drivers of UHPC with IC at super early hardening period are identified as the extra liquid volume compensation and the effect of thermal expansion. Furthermore, the rapid shrinkage growth stage of the UHPC matrix is governed by the hydration dynamic, while the sustained shrinkage growth stage is managed by cold shrinkage, chemical shrinkage and capillary pressure. Finally, the feasibility of the Powers model in the design of UHPC incorporating wet PFA is carefully revealed, and the key parameters for obtaining UHPC with advanced volumetric stability are elucidated. The strategy in terms of the autogenous shrinkage for the UHPC designed with PFA is revealed.
The geopolymer concrete has outstanding physical properties and positive impact on environment compared to conventional concrete. Present endeavor highlights a strategy for management of glass and limestone waste to recycle them in geopolymer concrete deep beams. In this study, 126 geopolymer concrete samples were made for investigating the mechanical properties of geopolymer concrete with the sand replacement ratio of 0 to 15% by weight in increments of 5%. In addition, seven Reinforced geopolymer concrete deep beams of 600,150,150 mm were casted with respect to the concrete mix and their performance was examined in four-point bending test as per ASTM C78/C78M considering sand replacing ratio of 0-15%. Moreover, proper material constitutive relationships were selected to simulate the performance of geopolymer concrete incorporating waste aggregate. Consequently, a nonlinear finite element solution in ANSYS 11.0 was developed using these constitutive models to predict the behavior of beams. Experimental observations revealed that the use of waste lime and waste glass aggregates reduced the compressive and tensile strength of geopolymer concrete. Furthermore, the loss in strength using waste glass aggregate was less than 15% when compared to geopolymer concrete with waste limestone. Whereas, 5-15% sand replacing with waste aggregate resulted in an average reduction of 19% in loading capacity of the deep beams. The degradation in the ultimate load of the beams with limestone aggregate was 46.6% lower than that for members containing waste glass aggregate. The strain energy of the deep beams containing waste limestone was enhanced by increasing the waste aggregate content from 5% to 15%. Whilst increasing the ratio of replacement for glass mixes led to a decrease in final compressive strain. The outputs of the numerical analysis, in terms of loading capacity of the geopolymer concrete deep beams, were in good matching with the experimental results.
This research work is aimed at establishing the percentage at which silt and clay content in river bed fine sands sourced in Abuja and environ are not suitable for concrete work. Fine aggregate samples were collected from five major locations within Abuja and environ namely: Bwari, Mararaba, Kuje, Jere and Gwagwalada. The percentage silt and clay content present in each sample was examined to be 9.76%, 9.68%, 5.7%, 2.99% and 15.38%, and named as samples 1, 2, 3, 4 and 5. Afterwards, sixty (60) concrete cube samples of 150 x 150 x 150 mm dimension were cast using a 1: 2: 4 mix ratio and water-cement ratio of 0.5 and cured for 7, 14, 21 and 28 days prior to crushing. In addition, the average compressive strength results of the samples were established. Thereafter, to determine the percentage of silt and clay content not fit for concrete works, sample five (5) was thoroughly washed and dried to zero moisture content and thereafter, eighty-four (84) standard concrete cubes of 150 x 150 x 150 mm dimension were cast using a 1: 2: 4 mix ratio and water-cement ratio of 0.5. The washed sand was partially replaced with processed silt and clay at 0%, 2%, 4%, 6%, 8%, 10% and 12% and crushed at 7, 14, 21 and 28 days. From the study, the percentage at which silt and clay content in river bed fine sands is not fit for engineering uses particularly concrete was established to be 7%.
This research work is aimed at establishing the percentage at which silt and clay content in river bed fine sands sourced in Abuja and environ are not suitable for concrete work. Fine aggregate samples were collected from five major locations within Abuja and environ namely: Bwari, Mararaba, Kuje, Jere and Gwagwalada. The percentage silt and clay content present in each sample was examined to be 9.76%, 9.68%, 5.7%, 2.99% and 15.38%, and named as samples 1, 2, 3, 4 and 5. Afterwards, sixty (60) concrete cube samples of 150 x 150 x 150 mm dimension were cast using a 1: 2: 4 mix ratio and water-cement ratio of 0.5 and cured for 7, 14, 21 and 28 days prior to crushing. In addition, the average compressive strength results of the samples were established. Thereafter, to determine the percentage of silt and clay content not fit for concrete works, sample five (5) was thoroughly washed and dried to zero moisture content and thereafter, eighty-four (84) standard concrete cubes of 150 x 150 x 150 mm dimension were cast using a 1: 2: 4 mix ratio and water-cement ratio of 0.5. The washed sand was partially replaced with processed silt and clay at 0%, 2%, 4%, 6%, 8%, 10% and 12% and crushed at 7, 14, 21 and 28 days. From the study, the percentage at which silt and clay content in river bed fine sands is not fit for engineering uses particularly concrete was established to be 7%.
This study designed a novel cement-based architectural tile prepared with more than 70% waste glass content (by weight). The waste glass was employed not only as decorative aggregates but also as a supplementary cementitious material in the architectural mortar. In terms of shrinkage, the incorporation of glass powder (GP) could significantly reduce the drying shrinkage of the glass mortars regardless of its fineness. When the glass mortars were subjected to high temperature (800 °C), the inclusion of GP into the mortars was more able to mitigate the flexural and compressive strengths losses as compared to the control glass mortar prepared without the use of GP. Furthermore, using the GP and glass aggregates simultaneously could effectively improve the resistance of the glass mortars to sulfuric acid attack and the positive effect was more pronounced when finer GP was incorporated. In particular, an encouraging result shows that the replacement of 20% cement by fine GP successfully suppressed the deteriorative alkali-silica-reaction (ASR) expansion caused by the glass aggregates. Also, the glass mortars incorporated with fine GP exhibited comparable or even superior durability properties than that of the fly ash blended glass mortar.
The use of 100% waste glass cullet (WGC) as fine aggregates in architectural cement-based mortar had been proven to be feasible in previous works. This paper reports a further study on investigating the influence of using waste glass powder (WGP) as a supplementary cementitious material on the properties of glass-based architectural cement mortars. The experimental results showed a good linear relationship between the particle size of WGP and the flow values of the fresh mortar, revealing that the particle size of WGP played an important role in controlling the workability. For the hydration of white cement, the inclusion of WGP not only affected the second exothermic peak of hydration but also changed the third peak. In particular, the result indicated that the use of finer WGP had an advantage in increasing the flexural strength of the cement mortar when compared with the corresponding compressive strength, which was attributed to the morphological and pozzolanic effect of WGP. In addition, the very fine WGP could act as micro-fibers and micro-aggregates in filling the microstructure of the mortar. At 90 days of curing, the mortar prepared with finer WGP showed a distinct improvement in strength due to the improved interfacial transition zone and the pore-size refinement.
This work was aimed at studying the fresh properties of cement-based mixtures containing waste glass powder (WGP) and waste glass cullet (WGC) obtained from crushed post-consumer beverage bottles. The experimental results show the setting time of the WGP modified pastes were prolonged due to the lower rate of hydration. Irrespective of the addition WGP, a good correlation between the early hydration characteristics and the stiffening or flowability can be established. However, during the first 30 min of hydration, the fresh properties of the WGP modified mortars were predominantly dependent on the particle size and the morphology of the WGP investigated.
This research was focused on the use of the modified Chapelle test as a direct laboratory methodology to access the pozzolanic activity of both experimental and commercial metakaolins. At the same time, this test was used in the evaluation of experimental metakaolins. This chemical test, performed during 16 hours at 90 °C, allows the quantification of portlandite fixed by the metakaolin sample. The calcium hydroxide that was not consumed is quantified by acid titration (HCl), and the test result is expressed in mg of fixed calcium hydroxide by g of metakaolin. According to this test, the pozzolanic activity of a metakaolin should not be less than 700 mg Ca(OH) 2 / g metakaolin. The modified Chapelle pozzolanic activity of six commercial metakaolins was evaluated between 920 and 1560 mg Ca(OH) 2 / g metakaolin. From the seven experimental metakaolins produced between 750 ºC and 940 ºC, a material with modified Chapelle pozzolanic activity value of 1240 mg Ca(OH) 2 / g metakaolin was obtained, which is similar to some tested commercial metakaolins produced at industrial scale. The metakaolin produced at 800 ºC was ground, resulting in a particle size reduction of ≈ 4x less and a consequent increase of 21 % in the pozzolanic activity.
Pollution resulting from hazardous glass (HG) is widespread across the globe, both in terms of quantity and associated health risks. In waste cathode ray tube (CRT) and fluorescent lamp glass, mercury and lead are present as the major pollutants. The current review discusses the issues related to quantity and associated risk from the pollutant present in HG and proposes the chemical, biological, thermal, hybrid, and nanotechniques for its management. The hybrid is one of the upcoming research models involving the compatible combination of two or more techniques for better and efficient remediation. Thermal mercury desorption starts at 100 °C but for efficient removal, the temperature should be >460 °C. Involvement of solar energy for this purpose makes the research more viable and ecofriendly. Nanoparticles such as Fe, Se, Cu, Ni, Zn, Ag, and WS2 alone or with its formulation can immobilize heavy metals present in HG by involving a redox mechanism. Straight-line equation from year-wise sale can provide future sale data in comparison with lifespan which gives future pollutant approximation. Waste compact fluorescent lamps units projected for the year 2015 is 9,300,000,000 units and can emit nearly 9,300 kg of mercury. On the other hand, CRT monitors have been continuously replaced by more improved versions like liquid crystal display and plasma display panel resulting in the production of more waste. Worldwide CRT production was 83,300,000 units in 2002 and can approximately release 83,000 metric tons of lead.
This paper presents an experimental study for the purpose of reducing the cost of producing ultrahigh performance fibre-reinforced concrete (UHPFRC). Reject fly ash (r-FA) and recycled glass powder (GP) were examined as replacement materials for the silica sand and cement used to prepare UHPFRC, respectively. In addition, curing UHPFRC specimens at 25 ° C and 90 ° C was investigated to determine differences in mechanical properties. The results showed that using r-FA and GP reduces the flowability of fresh UHPFRC. The use of GP increased the mechanical properties of the UHPFRC. Moreover, the test results indicate a significant improvement in the mechanical properties of plain concrete by the inclusion of r-FA as partial replacement of fine aggregate (sand) and can be effectively used in UHPFRC. Furthermore, specimens cured at 25 ° C give lower compressive strength, flexural strength, and fracture energy than specimens cured at 90 ° C .
Sustainable concrete is considered a very important material in building construction in terms of achieving sustainability pillars and improving its properties. It includes many recent types of construction concrete wastes, natural recycled wastes, and mineral materials. These sustainable concrete types are governed by several criteria leading to difficulty in determining the best. In this research, a sustainable concrete selection decision-making model (SCSDMM) was developed to support the selection of the best sustainable concrete by applying two modules. Module 01 utilized the fuzzy logic technique for evaluating the proposed criteria, which are controlled by several factors using logical rules for relating factor weights. Module 02 was based on the analytic hierarchy process (AHP), considering applying sustainability principles and aimed to support the final decision for determining the best sustainable concrete↱. The proposed model dealt with nine replacement materials to produce sustainable concrete mixes as alternatives. The comparison criteria included many characteristics of compressive strength, tensile strength, low water absorption , low environmental impact, cost savings, and recycled materials availability. The model was applied using data from two case studies in the Kingdom of Saudi Arabia (KSA) and Egypt. The results showed that compressive ↱strength ↱and low water absorption were rated as the most important criteria, while the importance of recycled materials availability represented the low-est↱. ↱The final decision favored using recycled natural powder (RNP) in KSA, followed by fine recycled concrete aggregate (FRNA). At the same time, silica fume (SF) was supported to be used preferably in Egypt, followed by fine recycled concrete aggregated (FRCA). To evaluate the model's robustness, sensitivity analysis tests were conducted to measure the effects of modifying criteria and alternatives' relative weights on the final decision. The SCSDMM can accept more concrete mixes alternatives and criteria as well as it can also be applied in other countries.
The addition of supplementary cementitious materials (SCMs), which is an effective method to reduce the CO 2 emission during the cement production, will change the autogenous shrinkage of early-age hydrating cementi-tious systems. In this paper the effect of different SCMs, i.e., silica fume and fly ash, on the physical properties and autogenous shrinkage of cement paste is studied, both experimentally and numerically. The experiment results show that autogenous shrinkages of cement pastes reduce significantly with the increase of water-binder ratio. The addition of fly ash will lead to smaller autogenous shrinkage while the influence of the dry densified silica fume on the autogenous shrinkage is not pronounced. A numerical simulation model, in which autogenous shrinkage is split up into an elastic part and a time-dependent part is proposed in this paper. The two parts are calculated separately. The simulation of the visco-elastic response of the cement paste to the internal driving force was performed by using a solidification theory model that takes the aging into consideration. The physical properties of different kinds of cement paste are experimentally investigated and the measured results are taken as input parameters of the simulation model. The simulated autogenous shrinkage of different kinds of cement pastes are compared with the measured results to verify the prediction of the proposed model.
The quick rise of intelligent technologies promotes the development of the construction industry into a new phase. As an advanced cement-based materials, ultra-high performance concrete (UHPC) breaks the performance upper limit of traditional concrete materials, which has also been empowered by intelligent techniques. Hence, this work comprehensively reviews the progress on the intelligent design and manufacturing of UHPC materials. The review mainly includes various design methods and performance characteristics of 3D printed UHPC (3DP-UHPC). The results reveal that currently, the particle packing methods, especially compressible packing model (CPM) and modified Andreasen and Andersen (MAA) model, are domain in designing UHPC materials. Meanwhile, the intelligent design methods, referring to optimal design by computer technology, are also increasingly used due to their high efficiency and accuracy in property predicting. Notably, recently, a new design concept was proposed by the joint use of particle packing models and machine learning techniques. On the other hand, the intelligent manufacturing of UHPC mainly refers to3DP-UHPC. Here, the rheology (especially thixotropy) and printability (pumpability, extrudability and buildability) are crucial for the manufacturing of 3DP-UHPC. Adding steel fibers can enhance the matrix strength, but also will increase the anisotropy of 3DP-UHPC by regulating fiber orientation. Overall, the intelligent development of UHPC is a significant direction for the construction industry, attracting increasing interest and attention. The outcomes of this study emphasize the advantages and significance of using intelligent techniques to design and manufacture UHPC materials, which holds great references and support for future construction projects.
Recycling the concrete washing wastewater (CWW) of ready-mix concrete plants is significantly important for saving hundreds of millions of tons of water and avoiding water and soil pollution. However, to directly recycle CWW to mix fresh concrete is particularly difficult due to its high alkalinity and high solid content with unstable compositions. To respond these challenges, a feasible approach involving carbonation treatment of CWW and subsequent recycling of the carbonized CWW (CCWW) for concrete mixing is proposed in this paper. To this end, the CWW carbonation test was firstly carried out and the compositional analysis showed that the CCWW became a stable suspension with uniform distribution of fine CaCO 3 particles, stable ions contents and neural pH value. The effects of CWW, CCWW and the tap water on the fresh cement pastes hydration and the mechanical and deformation properties of hardened cement pastes were then comparatively analyzed. The results supported that CCWW contributed to the improvement of workability of fresh paste, the increase of strength, the decrease of dry shrinkage and the pore refinement of harden paste. Approximate 16.6 million tons of CO 2 per year was estimated to be captured by this approach wemix concrete plants. Benefiting from the improved mechanical properties and extraordinary CO 2 sequestration capability, recycling CCWW for concrete mixing resulted in nearly half reduction in CO 2 emission.
In recent years, it has become imperative to conduct studies on the environmental effect of the construction industry on sustainability and develop strategies to mitigate sustainability risks. These mitigation strategies aim to protect natural resources and reduce waste accumulation. The life cycle analysis of buildings has been one of these studies due to the adverse environmental effects of the materials utilized in construction, particularly concrete. Specifically, how material use affects global warming and consumer desires for energy-efficient and environmentally friendly buildings. This study presents a comprehensive life cycle assessment of operational and embedded energy components that affect overall energy consumptions for concrete construction. Five concrete mixtures with varying percentages of sustainable recycled plastic aggregate were compared to a control mixtures made with normal weight and natural lightweight aggregates using a case study of a two-story residential building in Saudi Arabia. A life cycle assessment was initially used to estimate the embodied impact of producing the concrete. Then operational energy use was simulated using IES-VE. The weathering profile, transportation distance, and processing energy were all considered and calculated using site-based data for the environmental impact assessment components. The results demonstrate significant reduction of annual operational energy, carbon emissions and overall energy consumption of up to 15%, 13% and 21%, respectively. Therefore, the resulting green concrete system is more environmentally friendly due to the superior thermal performance over existing natural lightweight aggregates concrete. This evidence enables the ideas to be implemented, particularly in dry climate countries such as Saudi Arabia, where the average electricity use is very huge. Additionally, the study results suggest the possibility of permanently integrating plastic wastes into sustainable aggregate and its subsequent green concrete to reduce these wastes' adverse effects.
Waste glass powder (WGP) has been shown to help improve concrete properties. However, the enhancing mechanism needs to be explored from the interfacial transition zones (ITZs) at the micro level. This study aims to investigate the microtopography and cohesion behaviour of ITZs through modelled recycled aggregate concrete (MRAC). To highlight the difference, old and new mortars in MRAC were prepared with water-cement ratios of 0.45 and 0.40, respectively. WGP was used to replace 20 wt% of cement in new mortar to improve the performance of the new ITZ. Two groups of MRAC with three types of ITZs were successfully fabricated and studied. The property differences between the old ITZ, new ITZ without WGP and new ITZ with WGP were comprehensively evaluated and compared by phase distribution, chemical composition, and micromechanical properties. The results show that the new ITZ without WGP presented the highest porosity (avg. 7.29%) but higher calcium silicate hydrate (C-S-H) elastic modulus (avg. 11.89 GPa) than that in the old ITZ (avg. 4.33% and 10.37 GPa, respectively). WGP can effectively reduce the volume fraction of pores and cracks to 4.30%, because it reacted with calcium hydroxide (CH) within the new ITZ and the adjacent old mortar to generate a large amount of C-S-H gel with a Si/Ca ratio around 1.5. As for the bonding strength between the old and new mortars, it is necessary to further synthetically evaluate the cohesion of C-S-H and compactness of new ITZ to obtain more accurate results.
The present investigation evaluates the impact of the partial substitution of cement and microsilica (MS) by mineral admixtures such as calcium carbonate and milled glass powders on the drying shrinkage of ultra-high-performance concrete (UHPC) and ultra-high performance fiber reinforced concrete (UHPFRC). Two dosages with partial substitution of cement and MS were used in addition to another without any substitution as a reference. UHPFRC samples were obtained by adding a 2% (vol.) of steel micro-fiber to these three UHPC dosages. Incorporating calcium carbonate and recycled glass into concrete enhanced rheological properties, thereby decreasing the need for chemical admixtures and increasing cost-effectiveness. The findings demonstrated that the partial substitution of cement and MS reduced the drying shrinkage of both UHPC and UHPFRC with respect to the reference dosage. It was also observed that the reinforcement with micro-fibers, and the narrowing of the dosages of cement and MS, reduced the drying shrinkage up to 40% compared with the reference UHPC. The shrinkage of traditional UHPC concrete, after 2% straight steel fibers, reduced by 10.8, 18.1, 12.1, and 12.2% at 5, 15, 20, and 25 days, respectively. Nevertheless, by incorporating this volume of fibers into the calcium carbonate and glass powder mix, a considerable reduction (40.4, 28.3, 25.0, and 18.1%) was achieved at the same ages.
The primary objective of this paper is to study the combined influence of waste glass powder and waste glass sand as a partial replacement to cement and sand respectively in an attempt to produce eco-friendly concrete. Cement concrete mixtures, with waste glass powder contents varying from 5 % to 25 %, as cement replacement with 5 % incremental steps and the glass sand contents varying from 10 % to 50 % as fine aggregate replacement with 10 % incremental steps, were being experimented during the present study. The impact of waste glass powder on the setting time of cement was evaluated. Workability was investigated in terms of slump and flow percentage for concretes with all the above combinations of waste glass powder and waste glass sand. Compressive and split tensile strengths were found at the end of 7 and 28 days of curing for all the concrete mixtures. Durability tests viz., water absorption and rapid chloride penetration were also conducted on all modified cement concrete mixtures. Mixtures with 5 % glass powder and 10 % glass sand combination were found to be optimum with respect to both strength and durability properties. The use of waste glass had resulted in reduced the water absorption along with chloride ion penetration, thus proving to be highly advantageous. Micro structural investigations like FESEM and EDX analysis were also performed on the modified samples to observe the morphological and elemental changes, happening due to the concrete modification. Through this research study, a novel and an eco-friendly concrete with improved performance was proposed with an optimised combination of the waste glass powder and waste glass sand as cement and fine aggregate replacements respectively.
An innovative leader in cutting-edge sustainable concrete technology is ultra-high-performance glass concrete (UHPGC). Through the utilization of post-consumer glass, UHPGC technology can improve the environment. Due to the fact that these materials are neither biodegradable nor ecologically benign, any economic benefit from a reduction in the amount of waste dumped in landfills is undesirable. This endeavor reviews the previous research on the behavior of Ultra-High-Performance Concrete (UHPC) incorporating waste glass powder as an eco-friendly cementitious material. A summarization was performed as well for previous works which used milled waste glass to replace cement, Quartz Powder (QP), Silica Fume (SF) and Sand or Quartz Sand (QS) in UHPC mixtures. Thus, various applications of Waste Glass Powder (WGP) in UHPC and its fresh and hardened characteristics were examined. The paper also pursues updating the database for more experimental and numerical work on UHPC incorporating waste glass from different sources.
Improving energy conservation of buildings and promoting wastes recycling contribute to reducing CO2 emissions. This work developed a green high-performance lightweight concrete (HPLC) with good thermal insulation for energy-saving purposes. The HPLC was comprised of lightweight microspheres and sustainable ultra high-performance concrete (UHPC), which was prepared with a large volume of waste glass. For the glass-based UHPC, the use of glass cullet led to mechanical decrement, while the workability and mechanical properties were improved with the replacement of 50% cement by glass powder. Combining glass aggregates and powder in UHPC significantly enhanced its thermal insulation properties. Meanwhile, incorporating two kinds of lightweight microspheres in the glass-based UHPC further lowered the density and thermal conductivity of HPLC. The performance of HPLC was dependent on the physical characteristics of lightweight microspheres rather than their chemical reaction based on molecular dynamics simulation. The developed HPLC exhibited a low density (<2000 kg/m³) and excellent mechanical properties (compressive strength >100 MPa and flexural strength >35 MPa). The superior performance of HPLC was ascribed to the high pozzolanic reactivity of glass powder and its promotion on cement hydration, the low thermal conductivity of glass, the chemical reactivity of microspheres as well as their hollow nature for impeding heat transfer. The good flexure and thermal insulation performance would make this eco-HPLC a promising material for applications in energy efficient buildings and long-span lightweight structures.
It is widely accepted that Ultra-High Performance Concrete (UHPC) could be designed by the employment of Modified Andreasen and Andersen (MAA) particle packing model. However, the traditional MAA model only takes into account that dry particles reach the dense packing status under physical conditions, without considering the chemical hydration of wet cement particles. To solve this problem, this study adopts a physicochemical packing method to optimize the mix-design of UHPC through establishing a new equivalent particle size distribution of hydrated cement by applying a multilayer spherical shell model. Based on this, the mix proportion of UHPC is redesigned and the properties of the optimized UHPC are evaluated afterwards. The results show that the optimized mix-design leads to higher particle packing density of UHPC, thereby improving the durability on the premise of guaranteeing the workability and mechanical properties. Meanwhile, the optimized mix-design can also achieve denser micro structures of UHPC matrix, which provides a valuable reference to design UHPC more scientifically and reasonably.
Aggregate-bed concrete printing is a variant of particle-bed concrete printing, which uses cement mortar to selectively bind coarse aggregates. This paper presents the effects of mortar properties on the printed products. The void structures of printed products were investigated by 2D image analysis and scanning electron microscopy (SEM) observation at different cross-sections. Two factors are investigated for their effects on the printing quality: the strength and the plastic viscosity of the cement mortar. Increasing mortar strength increases the strength of the skeleton between coarse aggregates and mortar. Besides, increased plastic viscosity was found to increase the volume of coarse air void (> 0.5 mm), and therefore reduce the overall strength. Based on these results, this study gives the guideline on how to adjust the sand/cement (S/C) ratio and water/cement (W/C) ratio to improve the printing qualities of aggregate-bed printing. An empirical model was then proposed considering the influence of coarse air volume and the strength of the mortar.
The aggregate occupies the highest volume of concrete and alternative methods to replace it using waste materials or by-products are required which can consequently preserve the natural resources. This paper investigates the utilization of washing aggregate sludge (WAS) waste generated from a local aggregate quarry and ground granulated blast furnace slag (GGBFS) to manufacture sintered aggregate. The properties of sintered aggregate were characterized by physical and mechanical tests and microstructural analysis. The aggregate was incorporated in concrete as a substitute for the coarse aggregate to determine its effects on the physical, mechanical, and durability properties. Test results showed that the inclusion of sintered aggregate slightly reduced the oven-dry density and considerably increased the water absorption and permeable voids of concrete. The compressive strength and modulus of elasticity of concrete decreased by up to 16 and 15%, respectively, with increased sintered aggregate ratio. The chloride ion penetrability and chloride migration coefficient of the concrete insignificantly changed with the incorporation of sintered aggregate. The research outcomes indicated the possibility of manufacturing sintered aggregate using WAS and GGBFS and its efficient utilization in concrete production and the optimum replacement ratio of sintered aggregate was found as 30% which yielded 28-day compressive strength of more than 50 MPa and comparable durability properties with reference concrete.
Nano-silica (NS) as a non-conductive nanofiller was utilized to promote performance improvement of conductive seawater cementitious composite (NS-CSWCC) manufactured by ohmic heating (OH) curing at −20 °C. NS exhibited great advantage on improving the heating efficiency of OH cured sample. The peak temperature and temperature-increase rate of NS-CSWCC samples increased from 52.7 °C and 0.27 °C/min to 73.4 °C and 0.43 °C/min with NS contents varying from 0 to 0.8 wt%. The enhanced mechanism of NS on heating efficiency was thoroughly clarified. The mechanical property results showed that NS-CSWCC sample with 0.8 wt% NS addition endowed the compressive strength of 83.5 MPa, meeting an increase of 36.4% comparing with that of the sample with no NS addition, indicating the advantage of NS addition on improving the mechanical properties. Besides, NS could also lead to higher Cl⁻ binding ratio of OH cured samples. To be specific, the Cl⁻ binding ratio of the sample with 0.8 wt% NS addition met an increase of 35.1% comparing with the sample incorporating no NS. Detailed micro-physicochemical analyses were conducted to reveal the mechanism behind increased Cl⁻ binding efficiency.
Supplementary cementitious materials (SCMs) have attracted increasing research interests due to the energy-intensive process and high greenhouse gases emissions of conventional cement. Meanwhile, large amounts of domestic wastes such as waste glass are causing serious environmental issues due to their nonbiodegradable characteristic. Thus, recycling waste glass is a sustainable way to mitigate the environmental problem, conserve natural materials, minimize landfill spaces, and save energy during the recycling production process. This paper experimentally studied the effect of using waste glass powder (WGP) as an ordinary Portland cement (OPC) supplementary material on the paste specimens at ambient temperature and after exposure to high temperatures (800 °C, 1000 °C, and 1200 °C). The physical-mechanical properties such as workability, setting time, compressive strength, and bonding strength of the OPC paste samples containing different mass contents of WGP (0%, 10%, 20%, and 30%) were investigated and discussed. The potential alkaline aggregate reaction (ASR) effect of WGP on OPC was investigated by the accelerated mortar-bar method. The results show that the addition of WGP contributed to the workability but led to prolonged setting time of the OPC paste. On the other hand, the introduction of WGP in OPC mitigated the degradation of the OPC matrix under high temperatures and could reduce the ASR effect. Therefore, the WGP could be regarded as a feasible SCM to OPC to improve the safety of OPC-based structures both at ambient and under high temperatures.
Waste glass stockpiling is a significant issue in Australia with approximately 66 kilo tonnes of uneconomic and contaminated waste glass fines being produced each year in Victoria alone. The high level of contaminants in waste glass fines could be harmful to concrete while washing glass is not economical and sustainable. Limited research has investigated the effect of contaminants in waste glass fines on the performance of concrete, which has hampered its broader acceptance as a substitution for natural sand aggregate. In this study, the feasibility of utilising unwashed waste glass fines as a sand replacement at 10 wt. % was comprehensively investigated, under both laboratory and on-site conditions. Minor differences were observed in both mechanical and durability properties between concrete with and without waste glass fines at 10 wt. % replacement. Overall, this study found that the effect of contaminants in waste glass fines can be neglected when being used as a replacement for natural sand at 10 wt. %.
This paper reports the long-term field and laboratory-tested performance of concrete produced with 20 wt.% replacement of cement with powder waste glass (WG). Field investigations of WG concrete were carried out in a large-scale field project comprising of various segments subjected to harsh weathering conditions and service load over a period of about three years. While laboratory cured WG concrete and normal concrete specimens were tested in compression and flexure at various concrete ages ranging from 3 days to 300 days. After about three years of field exposure, concrete cores were extracted from various segments of the project and tested for compressive strength, moisture sorption, and abrasion resistance. A detailed survey of the various segments of the project was carried out to physically examine the state of WG concrete after three years of service. Test results of the field WG concrete showed enhanced compressive strength, up to 57% reduction in moisture sorption and up to 61% reduction in abrasion weight loss in comparison to normal concrete at 300 days of concrete age. Similarly, the laboratory tests showed 43% gain in compressive strength and 28% gain in flexural strength of WG concrete in comparison to that of normal concrete at 90 days of concrete age. Detailed physical examination of various project segments showed no signs of deterioration or material failure after three years of service. The field project also demonstrated the constructability of WG concrete similar to that of normal concrete.
This work presented an enhanced ohmic heating (OH) curing method to promote the ultra-high strength of conductive hybrid carbon fibers reinforced RPC (HCF-RPC). This novel curing method was conducted at normal pressure and temperature, but its curing performance was comparable to the autoclave (AC) curing that required strict equipment to provide high pressure and temperature. Hybrid carbon fibers (CFs) and carbon nanofibers (CNFs) were synergistically applied to enhance electric conductivity and heating efficiency of HCF-RPC. Effects of enhanced OH curing on the multi-structural evolution of RPC were clarified and further compared with AC and high temperature stream (HTS) curing. The results showed that enhanced OH curing endowed the curing temperature of ∼180 °C to stimulate the compressive strength of HCF-RPC to 104.5 MPa with ultrashort curing duration of 3 h. XRD and TG analyses demonstrated the promoted hydration effect of enhanced OH curing, additional hydration products (tobermorite and xonotlite) were only detected in the enhanced OH and AC cured samples. Furthermore, ²⁹Si NMR data revealed longer average chain length in the enhanced OH cured sample than that of the AC cured sample. Additionally, a refined micro- and meso-scale pore structure was observed in the enhanced OH cured samples from MIP and BET analyses. This work presents enhanced OH curing as an effective method to replace traditional heat treatment methods to rapidly prepare RPC structure.
Recently, with the rapid development of artificial intelligence (AI) techniques, there is a strong motivation to promote the intelligent development of the Ultra-High Performance Concrete (UHPC). To achieve this goal, this paper addresses an approach for precise design and characteristics prediction of UHPC by employing the Modified Andreasen and Andersen (MAA) model and Genetic Algorithm based Artificial Neural Network (GA-ANN) technique. Herein, 80 mixtures in total are conducted as a training dataset, and then a GA-ANN model is created for characteristics prediction of UHPC, which exhibits significant superiorities in fitting goodness and prediction accuracy compared to other classical prediction models. Furthermore, a prediction software based on GA-ANN technology with an efficient Graphical User Interface (GUI) is developed. Finally, a novel method for mix-design of UHPC by the use of MAA and GA-ANN models is proposed as follows: 1) conduct preliminary mixture design by MAA model; 2) further optimize the mixture by GA-ANN according to the property requirements. In general, a new UHPC with dense particle packing skeleton can be precisely designed by this method, which effectively verifies the feasibility of the application of AI technique in the UHPC field.
The behavior of concrete containing waste glass as a replacement of cement or aggregate was studied previously in
the most of researches, but the present investigation focuses on the recycling of waste glass powder as a substitute for silica fume
in high strength concrete (HSC). This endeavor deals with the efficiency of using waste glass powder, as an alternative for silica
fume, in the flexural capacity of HSC beam. Thirteen members with dimensions of 0.3 m width, 0.15 m depth and 0.9 m span
length were utilized in this work. A comparison study was performed considering HSC members and hybrid beams fabricated by
HSC and conventional normal concrete (CC). In addition to the experiments on the influence of glass powder on flexural
behavior, numerical analysis was implemented using nonlinear finite element approach to simulate the structural performance of
the beams. Same constitutive relationships were selected to model the behavior of HSC with waste glass powder or silica fume
to show the matching between the modeling outputs for beams made with these powders. The results showed that the loading
capacity and ductility index of the HSC beams with waste glass powder demonstrated enhancing ultimate load and ductility
compared with those of HSC specimens with silica fume. The study deduced that the recycled waste glass powder is a good
alternative to the pozzolanic powder of silica fume.
Mechanically more performant ultra-high-performance concrete (UHPC) was developed by incorporating waste liquid–crystal display (LCD) glass powder and modifying steel fiber geometry. For this purpose, 50% of inert silica flour was replaced by LCD glass powder, and five steel fiber types with various cross-sectional shapes (circular or triangular) and twisting rates were considered. Results suggest that the glass powder was effective in enhancing the tensile and flexural performance of UHPC with straight steel fibers due to the increased frictional shear resistance at the fiber/matrix interface. However, its effectiveness was diminished when the fibers were twisted. Better tensile and flexural performances were reported for the circular fibers than that reported for triangular fibers due to the minor matrix damage and higher pullout energy. Such performance and cracking behavior of the latter could also be improved by twisting the fibers through the torsional action. The single twisting of triangular fiber improved the performance of UHPC, and no further improvement was observed by increasing the number of twisting. Synthetically, the circular fiber or singly twisted triangular fiber was considered as the most appropriate reinforcing type of UHPC.
Concrete waste slurries coming from the washing of concrete mixer trucks in the manufacture of ready-mix concrete generate high costs and environmental impacts. In this work, we examined the consumption of raw materials, water, and generation of wastes for three Brazilian ready-mix concrete plants (that used different waste management strategies). The reuse of concrete slurry fines was also investigated in new concretes considering the waste management scenarios, production and operational costs. The strategy to recover fresh concrete provided the best scenario since it reduced significantly operational costs, despite the inclusion of new production cost, i.e. the hydration stabilizer additive. The replacement of sand with 1 vol.% concrete slurry provided adequate rheological conditions for concretes, when the water content increased up to 6 wt.% or added 0.3 % m.c. of polycarboxylate-based additive. The marginal increase in the production cost can also be compensated by the reduction of the disposal operational costs. The reuse strategy was not enough for the total elimination of concrete fines, requiring market diversification (e.g. precast concrete products); but fines availability can be very limited.
This paper presents the effect of various glass aggregates on plastic and drying shrinkage and alkali silica reaction (ASR) expansion of cement mortar. The study was done by substituting a portion of sand with expanded glass, crushed glass, and glass bead aggregates. The low absorption capacity of glass, except expanded glass, enhanced the dimensional stability of the mixtures, minimizing volumetric contraction associated with shrinkage. Presence of finer glass particles in the mortar resulted in a large benefit in ASR expansion. The study found that cement mortar with glass aggregates can be beneficial if aggregate type and amount is chosen appropriately.
This study investigates the rheological behaviour of ultra-high performance cementitious composite mortars containing 15–25 % of silica fume. The utilization of two Portland cements with different mineralogical compositions and their influence on yield stress of mortar was monitored. The coaxial rheometer was used for determination of flow curves of tested samples. It was found that besides the relation between flow and water-to-binder ratio, there is also a substantial relationship with the mortar composition, in particular with the content of silica fume. The yield stress can be described by an exponential function of volume content of solids in the mortar. Such a function can describe not only the influence of granulometry but also the impact of structure formation on early age Portland cement hydration. It was found that the estimation of yield stress can be done even by a simple modular in-field technique such as a spread flow test.
The rheology is an effective tool to characterize workability, consistency, flowability, and predict stability, pumpability, shootability, pressure of formwork, multi-layer casting. This paper presents a critical review on the rheological properties of fresh concrete in recent publications. The applicable rheological models for the flow of concrete are revealed. The effects of constituents of fresh concrete, including cement, supplementary cementitious materials (fly ash, ground blast furnace slag, and silica fume), limestone powder, coarse and fine aggregates, and chemical admixtures (superplasticizer, viscosity modifying agent and air-entraining agent) on the rheological properties are discussed in detail. The applications of rheograph and workability boxes in mixture proportioning and quality control are also illustrated.
Autogenous shrinkage is a major concern in early age cracking of high performance concrete (HPC). Low water-to-binder ratio and incorporation of supplementary cementitious materials (SCMs) can remarkably affect the pore structure, relative humidity, self-stress, degree of hydration, and interface structure; hence, increase the shrinkage in the matrix. In this paper, the mechanism of autogenous shrinkage of HPC and influential factors in its development are discussed. In general, autogenous shrinkage is more pronounced in HPC, albeit, using low heat cement, fly ash, shrinkage reducing agents, lightweight aggregates, and fibers can effectively reduce it. The effects of SCMs on autogenous shrinkage, relationship between different types of shrinkage and autogenous shrinkage as well as the effect of internal curing on autogenous shrinkage need to be further studied.
Ultra-high-performance concrete (UHPC) is characterized by a dense microstructure that yields ultra-high strength and durability properties. Quartz sand (QS) with maximum particle sizes of 600 μm represents the coarse particles in (UHPC). The QS with optimum grading curve is obtained from crushing coarse sand or rocks, however this is a time-consuming, costly, and polluting process. This paper reports on a study to determine the possibility of producing and using glass sand (GS) for partial or total replacement of QS in UHPC. The results show that GS with a mean particle size (d50) of 275 µm could be recommended as an optimal PSD to replace QS particles. The results demonstrate that compressive strength values of about 196 and 182 MPa after two days of hot curing can be achieved when replacing 50% and 100% of QS with GS, respectively, compared to 204 MPa for reference UHPC containing 100% QS. Incorporating higher replacement rates of GS was shown to produce UHPC of accepted flowability and dense microstructure that mitigated the aggregate alkali–silica reaction
In this study potential synergistic role of a finely ground glass powder in binary and ternary cementitious blends with conventional SCMs such as meta-kaolin, fly ash and slag was evaluated. Strength activity index, thermo-gravimetric analysis (TGA) and mortar bar tests were conducted to study the pozzolanic behavior and ASR mitigation ability. The results from this study showed that ternary mixtures consisting of finely ground soda glass with either slag or Class C fly ash out-performed binary mixtures consisting of each of these SCMs at an equivalent dosage level. Binary mixtures consisting of meta-kaolin out-performed ternary mixtures consisting of ground glass powder with meta-kaolin at equivalent dosage level. Among all the binary and ternary mixtures that contained 30% level of SCMs, the maximum strength activity index and the most efficient ASR mitigation was obtained in ternary mixtures consisting of at least 10% glass powder. The results from TGA studies supported these findings.
Recycling construction demolition waste such as concrete rubbles has become more important for preventing resource depletion and reducing environmental burden. However, recycled aggregate from demolished concrete waste can bring about several problems due to the various impurities included in concrete waste, when recycled aggregates are used for recycled aggregate concrete. Therefore, it is significantly important not only to investigate the influence of impurities on properties of recycled aggregate concrete but also to examine the safety of recycled aggregate.The objective of this study is to investigate the properties of concrete containing two types of metal impurities, of which limit content is not specified in standards. To achieve this purpose, experimental works were conducted for concrete containing metal impurities with various size and content and it was found that aluminum, contained in recycled aggregate, caused performance degradation in both mechanical property and durability of recycled aggregate concrete even with very low content less than 0.1%. This paper also suggested a convenient inspection method for aluminum impurity utilized at plants to confirm the safety use of recycled aggregate and to reduce the risk of using recycled aggregate.
The effects of replacement percentages and particle size distribution of recycled fine glass (FG) aggregates on the properties of dry–mixed concrete blocks were investigated. All the mixtures were proportioned with a fixed total aggregate/cement ratio of 4% and 50% of the total aggregate was fine aggregate. A total of 17 concrete block mixes, including a control (0% of glass) mix, were produced using four different particle sizes of FG (un-sieved, <2.36 mm, <1.18 mm and <600 μm) as replacements of sand. The replacement ratios were 25%, 50%, 75% and 100%. Properties such as packing density, hardened density and water absorption, as well as the effects of air and water curing upon 7 and 28-day compressive strength were studied.The results show that the water demand of the mix increased with decreasing fineness modulus of the fine aggregate. All concrete blocks containing FG showed higher water absorption and lower hardened density than the control concrete block. For FG with particle size less than 600 μm, this was more pronounced. Slight reductions in compressive strength were observed with the use of coarser FG, while significant increases in compressive strength occurred when the particle size of FG was reduced to less than 600 μm. This indicates that finer FG exhibited appreciable pozzolanic reactivity.
The aim of this paper is to assess the performance of self-compacting glass concrete (SCGC) after exposure to four elevated temperatures of 300°C, 500°C, 600°C and 800°C. The influence of curing conditions on the high temperature performance of SCGC was also investigated. For each curing regime, five SCGC mixtures were prepared with recycled glass (RG) which was used to replace natural fine aggregate at the level of 0%, 25%, 50%, 75% and 100%. After exposure to the elevated temperatures, concrete mass loss, density, water porosity, ultrasonic pulse velocity (UPV) and water sorptivity were determined and then a compressive strength test was conducted. The test results indicate that regardless of the exposure temperature, all the water cured specimens had higher residual strengths and mass losses while the water porosity and water sorptivity values were lower as compared to the corresponding air cured specimens. The incorporation of RG in the concrete mixes helped to maintain the concrete properties after the high temperature exposure due to the melting and resolidification of the recycled glass in the concrete matrix.
There is a growing interest of using recycled crushed glass (RCG) as an aggregate in construction materials especially for non-structural applications. Although the recycled crushed glass is able to reduce the water absorption and drying shrinkage in concrete products due to its near to zero water absorption characteristics, the potential detrimental effect of using glass due to alkali–silica reaction (ASR) in cementitious materials is a real concern. The extent of ASR and its effect on concrete paving blocks produced with partial replacement of natural aggregates by crushed glass cullet are investigated in this study. This study is comprised of two parts. The first part quantified the extent of the ASR expansion and determined the adequate amount of mineral admixtures that was needed to reduce the ASR expansion for concrete paving blocks prepared with different recycled crushed glass contents using an accelerated mortar bar test in accordance with ASTM C 1260 (80 °C, 1 N NaOH solution). In the second part, concrete paving blocks were produced using the optimal mix proportion derived in the first part of this study and the corresponding mechanical properties were determined.It was found from the mortar bar test that the incorporation of 25% or less RCG induced negligible ASR expansion after a testing period of 28 days. For mixes with a glass content of higher than 25%, the incorporation of mineral admixtures such as pulverized fuel ash and metakaolin was able to suppress the ASR expansion within the stipulated limit but the results need to be confirmed by other test methods such as the concrete prism test.The study concluded that the optimal mix formulation for utilizing crushed waste glass in concrete paving blocks should contain at least 10% PFA by weight of the total aggregates used.
A large proportion of the postconsumer glass is recycled into the packaging stream again, and some smaller proportions are used for a variety of purposes, including concrete aggregate. However, a significant proportion, which does not meet the strict criteria for packaging glass, is sent to landfill, taking the space that could be allocated to more urgent uses. Glass is unstable in the alkaline environment of concrete and could cause deleterious alkali-silica reaction (ASR) problems. This property has been used to advantage by grinding it into a fine glass powder (GLP) for incorporation into concrete as a pozzolanic material. In laboratory experiments, it can suppress the alkali reactivity of coarser glass particles as well as that of natural reactive aggregates. It undergoes beneficial pozzolanic reactions in the concrete and could replace up to 30% of cement in some concrete mixes with satisfactory strength development. The drying shrinkage of the concrete containing GLP was acceptable.
The possibility of using finely ground waste glass as partial cement replacement in concrete was examined through three sets of tests: the lime-glass tests to assess the pozzolanic activity of ground glass, the compressive strength tests of concrete having 30% cement replaced by ground glass to monitor the strength development, and the mortar bar tests to study the potential expansion. The results showed that ground glass having a particle size finer than 38 μm did exhibit a pozzolanic behavior. The compressive strength from lime-glass tests exceeded a threshold value of 4.1 MPa. The strength activity index was 91, 84, 96, and 108% at 3, 7, 28, and 90 days, respectively, exceeding 75% at all ages. The mortar bar tests demonstrated that the finely ground glass helped reduce the expansion by up to 50%. A size effect was observed; a smaller glass particle size led to a higher reactivity with lime, a higher compressive strength in concrete, and a lower expansion. Compared to fly ash concrete, concrete containing ground glass exhibited a higher strength at both early and late ages.
Quantities of waste glass have been on the rise in recent years due to an increase in industrialization and the rapid improvement in the standard of living. Unfortunately, the majority of waste glass is not being recycled but rather abandoned, and is therefore the cause of certain serious problems such as the waste of natural resources and environmental pollution. For these reasons, this study has been conducted through basic experimental research in order to analyze the possibilities of recycling waste glasses (crushed waste glasses from Korea such as amber, emerald green, flint, and mixed glass) as fine aggregates for concrete. Test results of fresh concrete show that both slump and compacting factors are decreased due to angular grain shape and that air content is increased due to the involvement of numerous small-sized particles that are found in waste glasses. In addition the compressive, tensile and flexural strengths of concrete have been shown to decrease when the content of waste glass is increased. In conclusion, the results of this study indicate that emerald green waste glass when used below 30% in mixing concrete is practical along with usage of 10% SBR latex. In addition, the content of waste glasses below 30% is practical along with usage of a pertinent admixture that is necessary to obtain workability and air content.