Jonathan E. OtiUniversity of South Wales · School of Engineering
Jonathan E. Oti
Doctor of Civil Engineering
About
66
Publications
45,119
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
950
Citations
Citations since 2017
Publications
Publications (66)
The deadline for the special issue is extended to 20 February 2023.
Discount for the Special Issue is as follows:
800 CHF for manuscripts submitted before 31 July 2022;
600 CHF for manuscripts submitted before 31 August 2022;
400 CHF for manuscripts submitted before 31 October 2022.
Evaluation of the effect of embodied carbon reduction using an optimized design section for a ground beam, use of supplementary cementitious materials, and replacement of normal aggregate with light weight aggregate on the mechanical properties of low-carbon concrete was carried out. A creep coefficient of 0.019 was estimated for a 365-day period o...
Clays encountered during road construction are mostly weak and result in major pavement failures due to their low California bearing ratio (CBR) and high swelling potential. In this study, sustainable and eco-friendly waste materials including brick dust waste (BDW), ground granulated blastfurnance slag (GGBS), recycled plastic (RP) and recycled gl...
The use of silica fume and ground granulated blast-furnace slag (GGBS) as a precursor to lime has been proven to be an effective sulfate soil stabilisation technique. However, which precursor is superior, in terms of both strength and swelling, is still questionable. Accordingly, the binary blends of lime–silica fume and lime–GGBS were separately a...
The role of gypsum level on the long-term strength and expansion of soil stabilised with different lime contents is not well understood. This research, therefore, studied the effect of varying gypsum concentrations of 0, 3, 6, and 9 wt% (equivalent to the sulfate contents of 0, 1.4, 2.8, and 4.2%, respectively) on the performance of sulfate soil st...
Sulfate-induced expansion resulting from the formation of ettringite in sulfate-bearing soil stabilised with calcium-based stabilisers is a problematic issue with technical and economic implications. Thus, this research examines the viability of the co-addition of lime (L) and silica fume (S) at varying binder dosages (4, 6, and 10 wt%), with a vie...
![Figure 5. Moisture content control chart (Section 3/9 of [48]). CBR...](profile/Samuel-Abbey/publication/359845318/figure/fig2/AS:1142940709732361@1649509708281/Moisture-content-control-chart-Section-3-9-of-48-CBR-tests-were-carried-out-for-all_Q320.jpg)
Abstract: Road pavement thickness and their depth of construction take a chunk of the overall cost of road construction. This has called for a need for reduced road pavement thickness by improving the engineering properties of subgrade such as the California bearing ratio (CBR). The CBR of road subgrade has been a major determining factor for road...
Dear Colleagues,
The building and construction sector has been identified by most governments worldwide as being responsible for between 50 and 60% of carbon emissions. This percentage is set to increase significantly as energy usage increases worldwide. The drive to cut carbon emissions to the point where society is making a “Net Zero” contributi...
Industrial and urban wastes have been generated over time due to urban development with severe environmental and health implications. This paper reports the valorisation of waste and industrial by-product (magnesium oxide waste – MG1 and Ground Granulated Blast furnace Slag – GGBS) to develop an alternative cementitious binder for suppressing swell...
In the present study, un-densified silica fume was reacted with a 10 M sodium hydroxide solution to produce the sodium silicate gel having a pH of 14. The calorimetry of the reaction was evaluated. The gel was dried to increase its density by almost 35%. Thereafter, the thermogravimetry of the gel was performed at temperatures up to 1000 °C. Except...
This Special Issue, which is particularly geared towards stimulating the debate on Low-Carbon Technologies and Sustainability, aims to help identify engineering problems, define and implement appropriate solutions, and evaluate their contribution to sustainable development. Sustainability and sustainable development have environmental, social, and...
The current study investigated the development of a sustainable thermo-chemical approach to effectively optimize MgO-waste activated GGBS formulations, using four types of magnesium oxide (MgO) waste materials with ground granulated blast-furnace slag (GGBS) to develop binary cementitious systems (MgO-GGBS). This stems from the expected complexity...
The effectiveness of using silica fume based sodium silicate in the production of metakaolin (MK) and ground granulated blast furnace slag (GGBS) based geopolymer was investigated. Un-densified silica fume was appropriately dissolved in a 10 M sodium hydroxide solution to obtain a sodium silicate alternative (SSA) solution having the SiO2/Na2O mola...
Treated bentonite-rich soils used as liner materials in landfills may provide an effective solution to the problems of increased void ratios upon swelling at reduced suction as well as desiccation cracking when suction is increased during desaturation. Accordingly, this study provides an understanding of the evolution of void ratio of the mixed mat...
The production of cement-based construction and building is set to continue increasing as demand worldwide continues to increase, especially where emerging economies need cement-based materials for housing and infrastructure. In the context of increased regulations to reduce the carbon footprint of the construction industry and to limit greenhouse...
Lime stabilisation is one of the traditional methods of improving the engineering properties of lateritic soils for use as subgrade and foundation materials for the construction of road pavements and highway embankments. Understanding the mechanical performance of lime-stabilised lateritic subgrades in terms of their durability under continuous wat...
This study covers an in-depth investigation into the properties and practicality of the utilization of up to 40% Alumina Waste Filler (AWF) as a partial Portland Cement (PC) replacement material. AWF is a by-product from the recycling of aluminium, produced when salt slag is smelted and cleaned. Its use in concrete will lessen the landfill requirem...
Expansion of soils has been found to produce significant negative economic and environmental impact on various civil engineering infrastructure. This impact is more deleterious in soils containing sulphates, when treated with calcium-based stabilizers such as Lime and/or Portland cement (PC). The reported study investigated the strength and swell c...
This paper reports on stabilised clay-hemp building material for sustainability and low carbon use. Ground Granulated Blast-furnace Slag (GGBS) was used as a partial substitute for conventional stabiliser (lime or Portland cement) to stabilise Lower Oxford Clay (LOC) incorporating industrial hemp. The development of stabilised clay-hemp building ma...
Ground Granulated Blast-furnace Slag (GGBS) and Pulverised Fuel Ash (PFA) were used to replace up to 60% of Portland cement (PC) in concrete. The testing program of the concrete included the determination of the consistency of fresh concrete, the measurement of the density and compressive strength of the hardened products cured for up to 56 days an...
Clayey soils endure adverse changes in strength and volume due to seasonal changes in moisture content and temperature. It has been well recognised that high cement content has been successfully employed in improving the mechanical properties of clayey soils for geotechnical infrastructural purposes. However, the environmental setbacks regarding th...
In the present study, physico-chemical investigations were carried out on hydrated lime produced from the limestone of the travertine outcrop of Bogongo in the South West Region of Cameroon. The aim was to evaluate the suitability of that hydrated lime as building lime. The raw material was characterized and then fired at 900 °C. The fired product...
Clay bricks are traditionally fired intensively, consuming high-energy supplies. Thus, developing unfired clay bricks of good engineering performance is novel and a significant achievement. The overall aim of this chapter is to report the possibility of manufacturing unfired clay masonry bricks at both laboratory and industrial scale. The laborator...
The overall aim of this chapter is to report the possibility of teaching materials for civil engineers in a slightly different way. Under the proposed change, the assessment criterion of the module was delivered through 50% laboratory coursework (coursework 1 to 10) and 50% closed-book examination. The students worked in groups, a total of 10 labor...
This chapter reports on the potential of using formative feedback on assessment to support student learning and improve the curriculum for material in a civil engineering module. Under this study, when the students were given the feedback of their assessment on a piece of coursework, they were asked to repeat the coursework taking on board all the...
The objective of the present work is to study the effect of RHA on the performance of fresh and hardened metakaolin geopolymer pastes with focus on tensile strength and microstructure. The metakaolin was partially substituted by 12.5–50% RHA in the solid mixes and reacted with 10 M sodium hydroxide solution at ambient conditions of 20 ± 3 °C and 70...
The preference of clay-based materials for sustainable construction is well-established. The establishment of sustainability credentials of emergent construction materials is very subjective, and most available tools are not fully equipped to deal with individual material systems, such as composite cement- or lime-based cementitious systems, includ...
The establishment of sustainability credentials of emergent construction materials is very subjective, and most available tools such as BREEAM, CEQUAL, ARUP SpeAR among others are not fully quipped or equipped at all to deal with individual material systems. The main problem emanates from the challenges of the audit of each aspect of the material p...
This chapter reports the potential of using Lime for the Stabilisation of Glacial Till Clay (GTC) incorporating Wheat Straw (WS) or Waste Tyre Rubber Granules (WTRG). WS is a readily available agricultural waste that is left over after the harvesting of the wheat grains. WTRG is a waste product obtained from shredding scrap tyres into a fine powder...
This research work reports the potential of using Brick Dust Waste (BDW) as a partial substitute for Portland Cement (PC) in the development of concrete. BDW is a recycled waste materials that is sourced from the demolishing of fired clay brick buildings or the discarded by-product materials from the cutting of fired clay bricks into shape and size...
In this study, the Compressive strength of concretes made with Ground Granulated Blast furnace Slag (GGBS),
Pulverised Fuel Ash (PFA), Rice Husk Ash (RHA) and Waste Glass Powder (WGP) after they were exposed 780 degree C (exposure duration of around 60 minutes) and then allowed to cool down gradually in the furnace for about 280 minutes at water bi...
This work reports the potential of using Palm Kernel (PK) ash and shell as a partial substitute for Portland Cement (PC) and coarse aggregate in the development of mortar and concrete. PK ash and shell are agro-waste materials from palm oil mills, the disposal of PK ash and shell is an environmental problem of concern. The PK ash has pozzolanic pro...
This paper reports the potential of using cereal ash and bottom ash waste generated from biomass combustion plants for the manufacture of stabilised bricks and sustainable masonry mortar for brick joints and plaster. For the stabilised brick production, the cereal ash waste and bottom ash waste were used as full substitutes for primary clay, while...
This work reports the potential of using Brick Dust Waste (BDW) as a partial substitute for clay in the development of unfired clay building materials (brick, block and mortar). BDW is a waste material from the cutting of fired clay bricks. There are various reasons necessitating the cutting of bricks — corner bricks, construction of chimneys, and...
This paper reports on the morphology and composition of the hydrated unfired brick. Lime or Portland Cement (PC) was used as an activator to an industrial by-product (Ground Granulated Blastfurnace Slag -GGBS) to stabilise Lower Oxford Clay (LOC) for unfired clay brick production. Small slices (of 2 mm thickness) from each of the unfired clay brick...
The last few decades have witnessed various approaches and strategies that are geared towards the achievement of global sustainability. The key drivers to these efforts have included the ever growing scarcity of natural raw materials and increasing awareness of the effects of climate change. These drivers have resulted in efforts by various governm...
The overall aim of this work is to investigate the carbonation of Calcium Hydroxide (CH) present in Portland Cement (PC) mortar which gives an indication of the likelihood of efflorescence using the thermogravimeric analysis. In order potentially suppress the efflorescence associated with PC mortar, we replaced up to 80% PC in conventional mortar w...
Oil and gas production plays an important role in world economics. However, a vital aspect of ensuring successful production of oil and gas as required depends a lot on the construction of the oil well and designed cementing slurry used. Improper oil well cementing slurry used for well completion can jeopardise oil production and the entire oil wel...
This paper presents the results of an investigation for the application of alumina filler wastes and coal ash waste for unfired brick production. Mechanical test and durability assessment were carried out on unfired brick test specimens made using marl clay soil and alumina filler waste as a target material, and 70% mix of coal ash waste were used...
This paper reports on designed non-fired clay mixes for sustainability and low carbon use. Ground Granulated Blastfurnace Slag (GGBS), an industrial by-product, was used as a partial substitute for conventional stabiliser (Lime or Portland cement) to stabilise Kaolinite Clay (KC) and Lower Oxford Clay (LOC), for sustainable and low carbon non-fired...
Currently there is a growing pressure on energy efficiency for new buildings in the UK and worldwide. This has arisen partly due to the increasing awareness of the public for sustainable building construction. In addition, there is pressure on building materials manufacturers, due to new government regulations and legislations that are targeting en...
Dr Jonathan Oti from the University of Glamorgan, the UK, shares his views on the development of unfired clay building materials for sustainable building construction. The development of unfired clay building materials for sustainable building construction is expected to solve the problems associated with conventional building materials, such bas f...
Currently there is a growing pressure on energy efficiency for new buildings in the UK and worldwide. This has arisen partly due to the increasing awareness of the public for sustainable building construction. In addition, there is pressure on building materials manufacturers, due to new government regulations and legislations that are targeting en...
This paper reports on freezing and thawing of stabilised clay brick incorporating a latent hydraulic binder. The latent hydraulic binder used for the stabilised clay bricks is an industrial by-product (slag) arising as an inherent consequence of iron production. Laboratory and industrial-scale masonry bricks were produced. In order to improve on th...
Blended mixtures of ground granulated blastfurnace slag and Portland cement were used in making sustainable masonry mortars suitable for brick joints and for plastering, with Portland cement mortar as control. The testing programme included the determination of a relationship between the mortar flow value and mortar water demand for a wide range of...
The potential of using slate waste generated from roofing slate production in the UK in various applications is reviewed and the environmental impact of the stockpile of slate waste is also assessed. The findings suggest that there is potential for using slate waste in many situations, including engineering applications. In order to reduce the envi...
This paper reports on a laboratory and theoretical method for determining the design values for thermal conductivity and thermal resistance of unfired clay masonry bricks from both experimental and theoretical design point of view. The paper describes the methodology of obtaining these values using the measured lower and upper lambda limits. In ord...
This paper reports on freezing and thawing of stabilised clay brick incorporating a latent hydraulic binder. The latent hydraulic binder used for the stabilised clay bricks is an industrial by-product (slag) arising as an inherent consequence of iron production. Laboratory and industrial-scale masonry bricks were produced. In order to improve on th...
This paper reports on the engineering properties and microstructure of concrete incorporating slate waste aggregates generated from roofing slate production in the UK. Various concrete mixtures were designed using different sizes of slate waste as aggregate replacement. Concrete produced with limestone aggregate was used as control. The results sho...
The potential of using slate waste generated from roofing slate production in the UK in various applications is reviewed and the environmental impact of the stockpile of slate waste is also assessed. The findings suggest that there is potential for using slate waste in many situations, including engineering applications. In order to reduce the envi...
This paper discusses the potential of using slate waste generated from roofing slate production in the UK in the manufacture of unfired clay masonry bricks. Ground granulated blast-furnace slag activated by lime and Portland cement were used to stabilise Lower Oxford Clay incorporating slate waste in the preparation of laboratory cylindrical test s...
This paper reports on the production of unfired clay masonry bricks at both laboratory and industrial scales. The laboratory-scale bricks were produced at the University of Glamorgan while industrial brick production was carried out at Hanson Brick Company in Stewartby, Bedfordshire. Lime-activated ground granulated blast-furnace slag and Portland...
This paper reports on the compressive strength and microstructure of unfired clay masonry bricks. Blended binders comprising of lime-activated Ground Granulated Blastfurnace Slag (GGBS) and Portland Cement (PC)-activated GGBS were used to stabilise Lower Oxford Clay (LOC) for unfired masonry brick production. The compressive strength of the stabili...
This paper reports on the potential of incorporating lime-activated Ground Granulated Blast-furnace Slag (GGBS) in the stabilisation natural soil for laboratory and industrial scale stabilised earth masonry bricks manufacture. GGBS is a by-product material from the iron making industry that arises as an inherent consequence of iron production. For...
The shortage of low cost and affordable housing in the UK has led to many investigations into new building masonry materials. Fired clay masonry bricks are conventionally used for mainstream masonry wall construction but suffer from the rising price of energy plus other related environmental problems such as high energy usage and carbon dioxide emi...
This paper discusses laboratory tests on Lower Oxford Clay (LOC) stabilised using different levels of lime (L) or Portland cement (PC), with and without blending with ground granulated blast-furnace slag (GGBS). LOC is used by Hanson Brick Company Ltd in the manufacture of fired ‘London’ bricks at the Stewartby brick plant in Bedfordshire. The rese...
This paper reports on an investigation on the use of ground granulated blast-furnace slag (GGBS) in the development of a sustainable unfired clay binder material for stabilised masonry-brick. The compressive strength of the stabilised masonry-brick, using a semi-processed industrial kaolinite clay soil and a ‘real’ clay soil (Lower Oxford Clay) com...
This study deals with an innovative way of developing low carbon unfired clay bricks. A further
development of this research work could lead to the formulation of other masonry units (blocks
and mortar). The obvious advantage of this product is its ability to minimise CO2 within the wall
of buildings with minimal heating or cooling. The bricks are...
This paper reports on energy usage and carbon dioxide (co2) reduction technology. It presents the results of laboratory tests on lime-stabilised Lower Oxford Clay (LOC) using different levels of lime, and Portland cement (PC), and using these traditional stabilisers blended with Ground Granulated Blast-furnace Slag – GGBS. LOC is the clay used by H...
This paper reports on innovative research efforts to develop building bricks using industrial by-products and the possible benefits in terms of technology, economy and care for the environment. A process of brick making by utilising a by-product of an industrial process is viewed as a step towards a more sustainable building construction. Laborator...
Projects
Projects (6)
The building and construction sector has been identified by most governments worldwide as being responsible for between 50 and 60% of carbon emissions. This percentage is set to increase significantly as energy usage increases worldwide. The drive to cut carbon emissions to the point where society is making a “Net Zero” contribution to carbon levels is essential to secure our future on this planet. In addition, the future of humanity and biodiversity is our biggest global challenge, wrapped up in the climate emergency. It is imperative that new sustainable construction and building material development has the possibility of unlocking the solutions to the current global challenges. This Special Issue brings together techniques and concepts from various distinct works, to examine, explore, and critically engage with issues and advances in sustainable construction and building materials that can both provide several environmental benefits and create cost-effective products. The papers collected in this Special Issue can help researchers and practicing engineers, construction and building material scientists, and low-carbon and sustainability practitioners to find more advanced techniques and alternative approaches towards sustainable construction and building material development.
