Payam Shafigh

Wenzhou University of Technology · College of Architecture and Energy Engineering

The high alkaline condition of concrete naturally protects embedded steel bars from corrosion by forming a passive protective film. The pH of concrete is generally high, but concrete with different mix compositions may have various pH values. The pH of concrete may decrease over time due to long-term mechanical, chemical, biological and physical fa...

Huge amounts of fresh water are used in the concrete industry every day. The quantity and quality of water play important roles in determining the quality, strength, setting time, and durability of cement-based materials (CBMs), such as paste, mortar, and concrete. Freshwater systems are under pressure due to climate changes, industrialisation, pop...

This study investigates the influence of using ground palm oil fuel ash (G-POFA) from 10%–30% as cement replacement (by weight) on the cement mortar’s pH under various curing conditions. These findings were supplemented by thermal gravimetric analysis (TGA). Moreover, the resistance of G-POFA blended cement mortars to water absorption and sorptivit...

Structural Health Monitoring (SHM) is a strategic tool for the monitoring and noninvasive assessment of the health state of existing structures’ infrastructures and systems and can provide decision support for reducing operational costs and risks throughout their life cycle. In that sense, this Special Issue presents six research papers and one rev...

The construction industry must consider not only the mechanical performances of structural materials but also their thermal performances for energy-efficient buildings. There exist conflicting thermal and mechanical properties between normal weight concrete (NWC) and lightweight aggregate concrete (LWAC). NWC with high mechanical strength exhibits...

This study reports the influence of different climatic ambient temperatures on the thermal properties of fiber-reinforced lightweight aggregate concrete (LWAC). Lightweight expanded clay aggregates (LECA) with steel (ST) and polypropylene fibers were used in the mix proportions. The steady-state thermal test was performed on concrete samples at the...

Self-compacting concrete (SCC) is a type of concrete with low flow resistance that may be cast and compacted by its own weight without the need for external vibration, bleeding, or segregation during the casting process [1, 2]. SCC saves costs by decreasing construction time, equipment, and expert personnel needs due to its ease of placement. Also,...

A vast amount of natural resources are required to produce concretes due to industrialisation and urbanisation, indicating that large quantities of raw materials are being utilised worldwide. The use of industrial wastes as an aggregate in concrete is highly recommended to promote sustainable development by reducing the consumption of natural resou...

Oil palm shell (OPS) concrete filled steel tube (CFT) columns are acknowledged to be a new type of sustainable composite column. In this type of column, the conventional coarse aggregate was partially replaced with OPS lightweight aggregate to provide a green composite column. This type of CFT column showed higher energy absorption and flexibility...

Cementitious materials are widely used in the construction industry. These materials have high compressive strength and huge environmental effects but low tensile and flexural strength. Thus, researching these materials to make them environmentally friendly is very important in terms of the sustainable development of the construction industry. In r...

A quantitative pH measuring method has been used to measure the pH of pure and blended cement mortars. The blended cement mortars incorporating supplementary cementitious materials (SCMs) such as fly ash (FA), ground granulated ballast furnace slag (GGBFS) and palm oil fuel ash (POFA) were used. Moreover, different variables affecting the pH values...

Healthy reinforced concrete should be highly alkaline to safeguard the passive protective film for reinforcement of steel bars against corrosion. pH measurement is gaining importance in research of cement-based materials (CBMs), such as paste, mortar and concrete, as well as in structural health monitoring and forensic engineering applications. How...

Changes in cement-based materials containing waste after exposure to elevated temperatures are an important aspect that should be studied in developing sustainable construction materials. Modified cement-based materials obtained using the industrial waste present robust engineering properties can lead to sustainable development. This work evaluated...

Drying shrinkage is an inevitable phenomenon that leads to cracks and eventually remarkable volume changes in hardened concrete. In this study, the drying shrinkage strain behavior of roller compacted concrete pavements (RCCPs) in two different curing conditions was investigated. The variables of RCCPs were coarse to fine aggregate (C/F) ratios of...

Utilization of concrete in construction industry has increased in last decades. Although, concrete has a lot of advantages, it is important to consider its negative impacts on environment. One of that negative impacts is depletion of natural resources. To protect environment and make concrete industry sustainable it is needed to find alternative ma...

The pH of cement-based materials (CBMs) is an important factor for their durability, sustainability, and long service life. Currently, the use of supplementary cementitious materials (SCMs) is becoming mandatory due to economic, environmental, and sustainable issues. There is a decreasing trend in pH of CBMs due to incorporation of SCMs. The determ...

Defects in buildings are related to the problems in their design, materials and construction. In reinforced concrete buildings, one major reason of causing defects is the change of concrete pH value. Naturally, concrete has high pH value from about 12.5 to 13.5. It is high in concrete due to existing oxide mineral of portlandite and alkali metal co...

The pH of concrete is an important factor for the durability, sustainability and long service life of concrete building structures. Naturally, the pH of concrete is high from about 12.5 to 13.5. The main reason of this high pH of concrete is the existing oxide mineral of portlandite and alkali metal contents in Portland cement. The pH of concrete d...

This study investigates the effect of using different amounts of superplasticizer (SP) (0.25% and 0.50%) on fresh and hardened properties, durability, ultrasonic pulse velocity (UPV), and thermal conductivity of two RCC pavements with cement contents of 12% (269 kg/m3) and 15% (325 kg/m3). The test results demonstrate that the use of 0.50% SP in RC...

Roller compacted concrete pavement (RCCP) became a proper alternative to conventional concrete pavement due to its cost-effectiveness and easier production. RCCP is a zero slump concrete with appropriate mechanical properties which make it to be a durable rigid pavement. It has lower drying shrinkage due to its lower water demand and less cement co...

Roller compacted concrete pavement (RCCP) became a proper alternative to conventional concrete pavement due to its cost-effectiveness and easier production. RCCP is a zero slump concrete with appropriate mechanical properties which make it to be a durable rigid pavement. It has lower drying shrinkage due to its lower water demand and less cement co...

This study investigated the thermophysical properties in terms of thermal conductivity, heat capacity, thermal diffusivity, density, compressive strength, water absorption, and sorptivity of cement mortars containing different percentages of oil palm boiler clinker (OPBC). The normal sand was replaced by 25%, 50%, 75%, and 100% of OPBC. Furthermore...

Cement-based materials (CBMs), such as paste, mortar and concrete, are highly alkaline with an initial high pH of approximately 12.0 to 13.8. CBMs have a high pH due to the existing oxide mineral portlandite and alkali metal contents in Portland cement. The high pH of concrete provides excellent protection and reinforces the steel bars against corr...

The energy required for the heating and cooling of buildings is strongly dependant on the thermal properties of the construction material. Cement mortar is a common construction material that is widely used in buildings. The main aim of this study is to assess the thermal properties of cement mortar in terms of its thermal conductivity, heat capaci...

: The increasing need for eco-friendly green building and creative passive design technology in response to climatic change and global warming issues will continue. However, the need to preserve and sustain the natural environment is also crucial. A building envelope plays a pivotal role in areas where the greatest heat and energy loss often occur....

Utilizing waste material in the construction industry is an effective way to protect the environment and minimize construction cost. Oil-palm-boiler clinker (OPBC) is a waste material obtained by the burning off solid wastes of the palm oil industry during the process of palm oil extraction. This study presents an investigation on the use of OPBC a...

Cement-based materials (CBMs) initially start their life at a high pH of about 12.5- 13.5, which is further reduced due to several factors. These include ageing, penetration of moisture, carbonation, chloride ingress, alkali leaching, corrosion, and other biodegradation processes. A less reported factor enhancing the above reduction is incorporatio...

The roller-compacted concrete pavement (RCCP) has the same ingredients as the pavement made of normal vibrated concrete (NVC). Microstructure images show that RCCP has higher pack density compared to NVC specimens. The 28-day compressive, splitting tensile, and flexural strengths of RCCP are by 9%, 4%, and 25% higher than those of NVC. The final wa...

Abstract: The purpose of this paper is to investigate the flexural behavior of over-reinforced concrete beam enhancement by bolted-compression steel plate (BCSP) with normal reinforced concrete beams under laboratory experimental condition. Three beams developed with steel plates were tested until they failed in compression compared with one beam...

This study presents an experimental investigation and finite element modelling (FEM) of the behavior of over-reinforced simply-supported beams developed under compression with a bolt-compression steel plate (BCSP) system. This study aims to avoid brittle failure in the compression zone by improving the strength, strain, and energy absorption (EA) o...

Oil palm shell (OPS) agro-waste aggregate was successfully employed to produce lightweight aggregate concretes. However, the high rate of drying shrinkage for this type of concrete can impair the intended functionality of the structures or reduce service life. In this study, drying shrinkage strain behaviour of normal-weight and lightweight aggrega...

Construction industry demands for high amount of raw material to produce concrete. The constant reduction of natural resources results in negative impact to the environment and lack of raw material. Promotion of utilization of agricultural wastes in production of concrete can minimize the environmental impact towards the sustainable development. In...

Advancement in the field of construction has given rise to the modification of conventional materials in order to utilize the full potential of their components to achieve high durability, strength, and other engineering characteristics. Construction materials should ideally be environmental friendly. These diverse requirements resulted in the inve...

Insulating interior side of external wall and finishing by cement plaster is one of the most appropriate methods of reducing annual energy consumption in available buildings. The aim of this study is to determine the optimum expanded polystyrene (EPS) and cement plaster thickness for bungalow building in Malaysia. The present study evaluates the ef...

Roller compacted concrete pavement (RCCP) became a proper alternative to conventional concrete pavement due to its cost-effectiveness and easier production. RCCP is a zero slump concrete with appropriate mechanical properties which make it to be a durable rigid pavement. It has lower drying shrinkage due to its lower water demand and less cement co...

Cement-based materials (CBMs) such as pastes, mortars and concretes are the most frequently used building materials in the present construction industry. Cement hydration, along with the resulting compressive strength in these materials, is dependent on curing temperature, methods and duration. A concrete subjected to an initial higher curing tempe...

Nowadays, more infrastructure projects require concrete to have a high durability in addition to high strength. High strength high performance concrete (HSHPC) was developed to solve those problems. The weaknesses of HSHPC are high cost of constituent material such as silica fume which is mostly used as supplementary cementitious material (SCM), hi...

Aggregate gradation is one of the most important property that influence the behaviour of roller-compacted concrete pavement (RCCP). There are some limitations for gradation of coarse and fine aggregates from the standards. Based on the ACI 211.3R, the content of sand size less than 75 mm should be between 2 to 8% of the total aggregates. To study...

Roller-compacted concrete pavement (RCCP), named from a construction method, is a drier mix-stiff enough to be compacted by a vibratory roller. RCCP's fresh and hardened properties are considerably influenced by a mix water. The maximum density method, having optimum moisture content at maximum dry density, is most commonly used for the mix proport...

Oil palm shell (OPS) is a biosolid waste in palm oil industry in the tropical countries which could be used as aggregate in concrete mixture. Since 1984, OPS has been experimented as natural lightweight aggregate in research studies to produce lightweight concrete (LWC). Medium and high-strength LWCs using OPS as coarse aggregate were successfully...

Concrete is the most widely used synthetic material in the world but it is also a significant source of greenhouse gas emissions. The reduction and utilization of waste and by-products is one of many challenges facing mankind in the modern world. Therefore, recycling of concrete demolition waste can provide opportunities for saving resources, energ...

Drying shrinkage in concrete can be attributed to loss of moisture, variations in temperature, and the chemical reactions of cement with water and carbon dioxide, is one of the most important parameters which affects the durability and service life of the concrete structures. Recently, the lightweight concrete has got a considerable attention to be...

The thermal conductivity (k-value) of cement-based materials like concrete is an important factor when considering the amount of heat transfer through conduction. The amount of heat loss through walls and roofs has a direct effect on the energy consumption of buildings. The steady state and transient methods are considered the two main thermal cond...

Roller-compacted concrete pavement (RCCP) is an economic and durable rigid pavement. Although about half century has passed since the first RCCP was implemented, information about this type of concrete is still limited. RCCP as a zero-slump concrete, has lower cement content than conventional vibrated concrete. Therefore, the quality of the aggrega...

Palm oil fuel ash (POFA) is generated from the combustion of oil palm waste. This ash is considered a disturbance to the environment since it is dumped without being profit return or recycled, thus causing environmental problems and human health hazards. However, it has been proven that POFA is a pozzolanic material that can be utilized as cement r...

Identifying new energy saving methods in the building sector is essential due to limited natural energy sources and the rising population. Thermal mass materials have the ability to absorb and store heat before releasing it later on when necessary. They act as heat sinks during the daytime and as heat sources during the nighttime. Thermal performan...

The aim of the present study is to investigate the effects of utilizing different processings of normal rice husk ash (RHA) and black rice husk ash (BRHA) on the mechanical and durability properties of high-strength concrete (HSC). Mechanical and durability properties of HSC were evaluated on concrete mixes containing unground BRHA and RHA and grou...

p>Construction industry demands for high amount of raw material to produce concrete. The continuous depletion of natural resources results in negative impact to the environment and shortage of raw material. To reduce environmental impacts of concrete production one way is to utilize by-product and waste materials as cement and/or aggregate replacem...

Lightweight concrete offers numerous benefits compared to normal weight concrete such as reduction in dead load and construction costs. One of the most common methods of producing structural lightweight concrete is the use of lightweight aggregates. The application of waste substances as cement substitutes or aggregates in concrete can support a so...

This study compares the engineering properties of normal weight concrete with those of concrete with two types of lightweight aggregates, namely, oil-palm-boiler-clinker (OPBC) concrete and lightweight expanded clay aggregate (LECA) concrete. OPBC is a porous solid waste from the palm oil industry, while LECA is an artificial and impenetrable mater...

Roller compacted concrete (RCC) is a rigid pavement with an advantages such as being durable, economical and eco-friendly type of concrete pavement that is well suited for applications such as heavy industrial and low-speed roads as well as arterial roads. Mass production of RCC for infrastructure development may lead to large amount of carbon diox...

Palm oil fuel ash (POFA) is an agro-waste byproduct disposed as landfills without being recycled. Ground POFA is a suitable supplementary cementitious material that can be utilized in different types of concrete. However, problems associated with the reduction of workability and early-age compressive strength of concrete, as well as limited replace...

Purpose The purpose of this paper is to review the concept of occupant behavior and its relation with indoor environmental quality (IEQ) and building energy consumption. The behavior is referred to any direct or indirect action, which is selected by an occupant to manage the unpleasant indoor environmental conditions. Thermal comfort, indoor air q...

Structural lightweight concrete plays an important role in the construction industry, especially for the high-rise buildings. It can only be produced using lightweight aggregates. Oil-palm-boiler clinker (OPBC) is a solid waste from the oil palm industry and could be used as lightweight aggregate in concrete mixture. However, the density of this li...

Water absorption test is used to evaluate overall performance of concrete in terms of durability. The water absorption of lightweight concrete might be considerably higher than the conventional concrete due to higher rate of pores in concrete and lightweight aggregate. Oil palm shell is a bio-solid waste in palm oil industry, which could be used as...

Oil-palm-boiler clinker (OPBC) is an agricultural solid waste sourced from the palm oil industry in tropical regions. This study investigates the use of OPBC as coarse aggregate instead of conventional coarse aggregates to produce a greener concrete, which will help in implementing sustainable construction practices by reducing the usage of raw mat...

The benefits of using structural lightweight concrete in construction industry, particularly in high rise buildings, over normal weight concrete are numerous. The main method of producing structural lightweight concrete is the use of lightweight aggregates instead of ordinary aggregates in concrete. Due to the limited resources for natural and arti...

Lightweight concrete (LAWC) has numerous advantages over normal weight concrete (NWC), such as less dead load and construction costs. Using lightweight aggregates (LWA) is one of the most typical methods of fabricating structural LWAC. This paper studies the possibility of LAWC production by agricultural solid waste, specifically oil palm shell (OP...

Oil-palm-boiler clinker (OPBC) is an agricultural solid waste from the incineration process of solid wastes in palm oil industry. The OPBC that is highly porous and lightweight in nature is suitable to be used as a lightweight aggregate. This paper presents a method to produce high-strength lightweight aggregate concrete using OPBC. The workability...

Lightweight concrete offers numerous benefits compared to normal weight concrete such as reduction in dead load and construction costs. One of the most common methods of producing structural lightweight concrete is the use of lightweight aggregates. The application of waste substances as cement substitutes or aggregates in concrete can support a so...

The use of structural lightweight aggregate concrete in structures has several benefits over normal weight concrete, particularly in multi-story buildings. The best way to produce structural lightweight concrete is by using lightweight aggregates. The use of artificial aggregates was minimized because of the high production costs due to huge consum...

High strength lightweight aggregate concrete (HSLAC) provides many advantages to construction industry, especially in the reduction of structure’s dead load. Incorporating waste materials in HSLAC promotes to implement sustainable practice, minimize the negative impact to environment and reduce the cost of product. Oil-Palm-Boiler Clinker (OPBC) is...

The flexural behaviour of strengthened reinforced concrete (RC) beams is more complicated compared to the normal beams due to the different bond conditions and properties of the externally bonded material. A significant number of research studies have been reported on the use of different types of material for flexural strengthening of RC beams usi...

Nowadays, one of the most important construction materials is concrete. By the advances of the industries in the urban areas, concrete is considered as one of the highest demands. As a result, the large amount of unprocessed materials is needed for making concrete. In the meantime, the agricultural wastes and solid material disposal are giving seri...

Palm oil fuel ash is an supplementary cementitious material (SCM) generated from the combustion of palm oil fibers and shells in palm oil mills to produce electricity, and One approach to reduce the carbon dioxide emissions and increase the sustainability of concrete by substitute a significant amount of ordinary Portland cement (OPC) with it. This...

Concrete industry is one of the major sources of consuming high volume of natural resources. On the other hand, cement industry is a significant point source of carbon dioxide emissions due to the decomposition of raw material and burning fuel during the manufacturing process. As the demand for concrete is growing, one of the effective way to minim...

The aim of this study was to produce a sustainable construction material by incorporating an agricultural solid waste, namely oil palm shell (OPS), in an artificial lightweight aggregate concrete. For this purpose, in a structural lightweight aggregate concrete made of expanded clay, the lightweight aggregate was substituted with OPS in 0, 25 and 5...

The agricultural industry is a source of many types of solid waste. For instance, oil palm shell (OPS), is a waste from the palm oil industry and is produced in enormous quantities in tropical countries. This waste material is considered to be a major problem in terms of pollution, while, on the other hand, normal concrete needs a large amount of t...

Indoor Environmental Quality (IEQ) is an important topic which impacts on occupant health, productivity and also energy consumption in buildings. The four main parameters for IEQ evaluation are: Thermal comfort, indoor air quality, visual comfort and aural comfort. The occupant behavior in buildings defines as any direct or indirect act which an oc...