The utilization of traditional supplementary cementitious materials (SCMs) has become more intense in the concrete industry due to their better long-term properties. This research evaluates the fresh and hardened properties of concrete that was developed using a high amount of recycled aggregate (RA) incorporated with sustainable SCMs. Rice husk ash (RHA), palm oil fuel ash (POFA) and palm oil clinker powder (POCP) were used as SCMs at 10%, 20% and 30% cement replacement levels to investigate their positive role in the performance of RA concrete. The results showed that the 10% replacement level of cement by RHA produced the highest strength at all ages tested. Although POFA and POCP were found to negatively affect the strengths at an early age, the hardened properties showed improvement after a relatively long curing time of 90 days. In addition, the targeted compressive strength of 30 MPa was achieved by using SCMs at levels up to 30%. Overall, the sustainable SCMs can reduce the quantity of cement required for concrete production, as well as reduce the conventional cement with the industrial by-products, which are considered as waste materials; thus, the concrete produced using up to 30% of SCMs as a replacement for cement could be considered as more environmentally-friendly concrete.

Masonry and rendering mortars are is well known oldest techniques in the building. A common idea is to use strong material as possible, and as a result mortars are often rich in cement. Not only this is unnecessary expensive, it has also technical disadvantages and harmful to environment. Hence, in this study focuses on utilisation of palm oil mills waste, namely palm oil clinker powder (POCP) and POCP influences on the fresh and mechanical properties of masonry mortars are analysed and comparison between cement-lime (CLM) and masonry cement mortar (MCM) are addressed. The masonry mortars were prepared using cement-lime and masonry cement as control masonry mortars christened as type 'S' mortar. The POCP used as cement replacement material in the masonry mortar mixture from 0-80% by volume in the preliminary study and ideal replacement of 40% was used in the final mixture of mortar for comparison. All specimens were cured in water and air curing regimes for 7, 28 and 56 days and the physical and mechanical properties were analysed. The results show that as replacement of cement with POCP increases, there is a reduction in fresh density with subsequent increase in air content. Further, the use of masonry cement with POCP (MCP) shows highly workable mix even at lower w/cm ratio compared to cement-lime mortar with POCP (CLP). Moreover, CLM, CLP obtained higher strength (28 & 20 MPa) than MCM and MCP (24 MPa & 11 MPa). on the contrary, the cement-lime mortar with POCP shows higher compressive strength compared to masonry mortar prepared with masonry cement-POCP.

The manufacture of cement leads to almost 5 to 7% of the total production of carbon dioxide which causes greenhouse effect. So, it is vital to replace the ordinary Portland cement by the other binders which have the similar or better properties than cement. Besides, the recent interests on the palm oil industrial wastes in the development of mortar led to research works on usefulness of these wastes in construction materials. The palm oil industry produces many wastes such as oil palm shell, palm oil fuel ash (POFA) and palm oil clinker powder (POCP). In this research work, an experimental study was conducted to investigate the effects of different binder contents, and water-binder (w/b) ratio on the development of mortars. Conventional ordinary Portland cement was replaced with 40% of POCP and the total binder contents of 450, 500 and 550 kg/m3 with w/b ratios of 0.45, 0.35 and 0.32 used. The properties of mortars were evaluated for fresh and hardened properties; XRD characteristic was also studied. Test results showed that the strength of mortar specimens improved as the binder content increased with subsequent decrease in w/b ratio. POCP mortar specimens with binder content of 550kg/m³ with cement replacement of 40% produced 28-day compressive strength of 45.3 MPa, compared to 65.12 MPa for control cement mortar (CM). The value of flow diameter of 40% replacement of POCP mortar was 108.51 mm and this was 16.6% lower compared to control mortar. Though POCP based mortar produced a strength reduction of about 36.6%, its usefulness in achieving acceptable strength and sustainable aspect of reducing 40% of conventional cement could be considered significant.