Malaysia is one of the largest palm oil producers in the world and its palm oil industry is predicted to generate a large amount of waste, which increases the need to modify it for sustainable reuse. The green geopolymers produced from industrial waste can be a potential substitute for cementitious binders. This type of polymer helps reduce dependency on cement, a material that causes environmental problems due to its high carbon emissions. Palm oil fuel ash (POFA) geopolymer has been widely investigated for its use as a sustainable construction material. However, there is still uncertainty regarding the total replacement of cement with POFA geopolymer as a binder. In this study, we examined the effects of different material design parameters on the performance of a POFA-based geopolymer as a building material product through iterations of mixture optimisation. The material assessed was a single raw precursor material (POFA) activated by an alkaline activator (a combination of sodium hydroxide and sodium silicate with constant concentration) and homogenised. We conducted a physical property test, compressive strength test, and chemical composition and microstructural analyses to evaluate the performance of the alkali-activated POFA geopolymer at 7 and 28 days. According to the results, the optimum parameters for the production of alkali-activated POFA paste binder are 0.6 liquid-to-solid ratio and 2.5 alkaline activator ratio. Our results show that the use of alkali-activated POFA geopolymer is technically feasible, offering a sustainable and environmentally friendly alternative for POFA disposal.

This paper presents an investigation on lightweight foamed concrete (LFC) with different type of additives. LFC with 600, 1000 and 1400 kg/m³ density were cast and tested. Fly ash, lime and polypropylene fibre were used on each density with different percentages. All the additives effects were compared with normal LFC as control mix. Mechanical properties of LFC were evaluated with several tests up to 180 days. The results show that the drying shrinkage, compressive strength and flexural strength are affected by the hydration process of each additive in the harden LFC. Fly ash as pozzolanic material helps to strengthen the LFC, though it needs longer curing period to achieve ultimate strength. Lime gives slight contribution to strength as detail investigation on microstructure formation will give clear answer on how the mechanical properties were affected. The addition of polypropylene contributes to flexural strength and shrinkage of LFC. Polypropylene fibre only contributes to compressive strength at low LFC density.

Traditionally, Ultralightweight Foam Concrete (ULFC) is primarily used to replace filling excavations, ditch restoration and underground channels, because of their high porosity, water absorption and low strength. Yet, ULFC is characterized by excellent thermal properties and could be an alternative for sustainable energy-efficient building material. This study investigates the properties of an ULFC strengthened with alkali-treated banana fibre. The low density ULFC of 600kg/m3 was fabricated and strengthened with alkali-treated banana fibre. Fibre volume fraction of 0.25%, 0.35%, 0.45% and 0.55% were compared to the unreinforced specimens, serving as the control specimen (no fibre addition). Mix proportioning of 1:1.5:0.45 of cement, sand, and water was respectively adopted throughout the mix. The alkali treated banana fibre strengthened ULFC was tested for compressive strength, sorptivity and thermal properties. Morphology of the treated fibre and ULFC composites was studied using SEM micrograph. The result depicts that ULFC exhibited the optimum compressive strength of 1.1604N/mm2 with the fibre volume fraction of 0.35%. Sorptivity or rate of water absorption was testified to upsurge, after 24 hours duration at fibre volume fraction of 0.55%, recording a 56.12% increment compared to the control specimen. The finding displays that at the highest-fibre volume fraction of 0.55%, thermal conductivity and diffusivity decrease by 13.17% and 28.16%, correspondingly, whiles the specific heat capacity increases to 37.17% all compared with unreinforced specimens. SEM images reveal that the presence of lumen and the nature of porous and fibrous alkali-treated banana fibre. Hence, it is endorsed that ULFC produced with alkali-treated banana fibre should be utilized as an infill material for composite system.

Achieving energy efficiency particularly in Iraq is very critical due to continuous energy crisis since the 1990s. One of the major cities, Basra City faced this crisis since 2003 with energy generation declining by 26.4%. The building industry in Iraq represents the largest demand of energy, mainly in residential sector. In fact, most residential buildings depend on conventional construction system. In the past, the traditional system used to provide comfortable conditions during summer and winter. However, because of the increasing effect of global warming and technological advancement, this constructional system is no longer viable. Currently, the Industrial Building System (IBS) represents one of industrialization approaches which aims to enhance building quality and performance. However, the prefabrication construction system is rare and scarce in this country. Based on previous scenarios and researches, this study aims to investigate and compare the level of energy efficiency in the conventional system and IBS. Since it is difficult to collect data because of instability and insufficient provision of energy generation, the study was based on a simulation approach by using the EnergyPlus software to evaluate the actual condition. The study targeted an existing house in Basra (two-stories) with built-up area of 135m2. The performance was measured on the two systems throughout the year. The findings showed that the annual energy demand for cooling and heating for the conventional system was 19,311.99kWh while the IBS performed efficiently with 7374.57kWh. As a result, IBS reduced the annual energy consumption of 37.32% for heating and 65.36% for cooling