The potential use of waste recycled glass in concrete as recycled glass sand (RGS) and pozzolanic glass powder (PGP) was examined in this study. No major difference was found in compressive strength of concrete with the presence of RGS as sand replacement. While, the compressive strength of concrete reduced by 16 and 10.6% at 28 and 364 days respectively when 20% of Portland cement was replaced by PGP. The potential expansion of concrete due to alkali-silica reaction (ASR) was monitored according to the procedure of British Standard BS 812 Part 123:1999. As a siliceous material, the use of RGS as sand replacement in concrete possesses high risk of ASR expansion. Therefore, cracks were observed when RGS was used as sand replacement in concrete without any precautions to minimize this risk. Different materials were used as ASR suppressors to mitigate the potential risk of ASR, such as: ground granulated blastfurnace slag, metakaolin, PGP, and lithium nitrate ( LiNO3 ) . The expansion associated with ASR was...

To improve the prediction of compressive strength and embodied carbon of low carbon concrete using a program algorithm developed in MATLAB, 84 datasets of concrete mix raw materials were used. The influence of water, silica fume and ground granular base slag was found to have a significant impact on the extent of low carbon concrete behaviour in terms of compressive strength and embodied carbon. While the concrete compressive strength for normal concrete increases with reducing water content, it is observed that the low carbon concrete using lightweight aggregate material increases in compressive strength with an increase in embodied carbon. From the result of the analysis, a function was developed that was able to predict the associated embodied carbon of a concrete mix for a given water-to-cement ratio. The use of an alkaline solution is observed to increase the compressive strength of low carbon concrete when used in combination with ground granular base slag and silica fume. It is further shown that ground granular base slag contributes significantly to an increase in the compressive strength of Low carbon concrete when compared with pulverised fly ash. The optimised mix design program resulted in a 26% reduction in embodied carbon and an R² value of 0.9 between the measured compressive strength and the optimised compressive strength.

Using waste plastics as a partial natural aggregate replacement and monitoring strength and workability reduction in pavement structures is vital to net-carbon zero. This study explores the utilisation of waste plastic as a fine aggregate replacement in medium-strength reinforced concrete pavements, for improving plastic aggregate performance and the intrinsic reasoning for observed strength performance. Various weight fractions of fines were substituted by the same weight of plastic aggregates ranging from 5–15% according to the appropriate standards (Eurocodes and British Standards). The physical and mechanical properties of the composites were analysed. The results indicated that the use of polymeric materials as a partial replacement for fines contributed to a decrease in workability, compressive strength and push-out bond between steel reinforcement and concrete. Despite these trends, 5% replacement of fine aggregates with plastic waste surpassed all the feasibility criteria. Furthermore, using 10% of plastic replacement by weight was deemed feasible in non-structural applications such as roads, pavements, and facades. The outputs have demonstrated environmental engineering concepts in tackling plastic waste, providing an alternative to conventional aggregate. Environmental benefits can arise due to the removal of potentially hazardous plastics from entering ecosystems as well as minimising dredging of global sand reserves.

This study investigated improving bamboo–concrete bond by increasing mechanical interlock. Pull-out tests were used to measure the bond between bamboo and concrete. Corrugated and non-corrugated bamboo splints were tested, with four different patterns of corrugation. The effectiveness of using linseed oil for waterproofing corrugated and non-corrugated bamboo splints was also investigated. The bond stress and slip at the loaded and free ends were measured and recorded. The results show that the bamboo–concrete bond can be improved with the use of waterproofed corrugated bamboo splints. The bond achieved using waterproofed corrugated bamboo splints was comparable to the bond achieved using splints treated with expensive epoxy treatments. Although certain patterns were found to be more effective in achieving a strong bond with concrete, all the corrugation patterns with 2 mm projections achieved better results in comparison with non-corrugated splints. Linseed oil was found to be effective in improving the bond between corrugated splints and concrete.