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The increase in the concrete demand due to the rapid industrialization and urbanization may lead to a shortage of natural resources. Therefore, the use of recycled material in the batching of concrete will be helpful to meet the demands of the time without compromising the quality of concrete production. One such waste material produced in Pakistan is waste marble powder (WMP) that is generated from the marble factories during cutting of the marble stones, which in turn have a damaging effect on the environment. This study is based on the utilization of WMP as a partial substitute of the sand in concrete production and its various effect on the mechanical properties of the concrete. Different types of tests (unit weight, workability, compressive strength, splitting tensile strength, and water penetration) were carried out at 0-80%, of sand replaced with WMP, at increments of 20%. In all mixes, the ratio of water to cement was kept constant and the effects of curing conditions were studied at 14, 28, and 70 days. It was observed that with the incorporation of WMP, the workability and unit weight of concrete decrease proportionally to replacement percentage, whereas mechanical properties of concrete increase up to a certain percentage and then decrease. The maximum improvement in compressive strength was achieved at a 40% replacement, with a slight improvement in the tensile strength at 20% replacement. The water penetration test revealed a decrease in permeability with the increase in WMP percentage. Based on the results, it was recommended to use WMP up to 40% in the concrete mix as a replacement of sand.

This paper discusses on the compaction effect to the hydraulic conductivity performance for the sedimentary residual soil mixed bentonite. This mixture is proposed as a barrier material in landfill area and may possibly potential materials for use as compacted soil liners in landfills for leachate protection. A laboratories series was conducted to evaluate the effectiveness of compaction characteristics on sedimentary residual soil mixed with different percentage of bentonite (5%, 10% and 15%). The sedimentary residual soil sample was used in this study and was collected in sedimentary residual formation area in Salak Tinggi, Malaysia and named as Salak Tinggi soil. The mixed samples were compacted at three different compaction effort with different energy to determine the maximum dry density (MDD) and optimum moisture content (OMC). Then, the permeability test to determine the hydraulic conductivity (k) was conducted at MDD condition at every compaction effort at effective stress of 100 kPa. The results show that the MDD value were slightly low for the entire soil sample mixed with bentonite at all compaction energy level. Instead it shows all the three different compaction efforts applied to the mixed soil samples with bentonite yielded hydraulic conductivity less (k ≤ 1x10−9m/s). In fact, the increment of bentonite content also resulted in lower of MDD value and hydraulic conductivity value. However, MDD values were found to be higher for mixed soil when compacted with high compaction effort. The results of hydraulic conductivity tests demonstrated that hydraulic conductivity, k ≤ 1x10−9m/s can be achieved just by using lower compaction energy for the soil mix with bentonite. Instead it considered as suitable materials for liner due to the hydraulic requirement for soil barrier, k ≤ 1x10−9m/s. This finding show that compaction efforts play an important role for workability of the mixtures and significantly to be used as compacted of soil liner materials.

The consumption of agricultural and industrial wastes has grown rapidly across the world which leads to create large quantities of wastes. It reflects the problem of having a limited number of landfills due to a huge amount of waste produced. Therefore, the solution is recycle the agricultural and industrial wastes as one of the materials use in concrete. Agricultural and industrial wastes were selected as cement replacement in a concrete production. This study aims to investigate the concrete properties containing palm oil fuel ash (POFA) and ceramic tile wastes, such as workability, compressive and splitting tensile strength. The concrete mix design ratio was designed for concrete grade strength 30 and water cement ratio of 0.55. Testing for compressive strength was measured at 7 and 28 days and for tensile strength only at 28 days. This research finds that with combination of 5% POFA and 10% ceramic with 27.1 MPa for compressive strength and 2.5 MPa for tensile strength will be the optimum mix design to replace cement in concrete. This research helps to improve the knowledge, increase the level of environmental awareness and understanding the importance and recycling the construction waste generated.