The production of concrete emits greenhouse gases which aggravate global warming. Meanwhile, ceramic tile wastes generated from manufacturing factories, construction sites, and building demolition projects disposed of by landfills create land and water pollution. Therefore, in this study, the suitability of ceramic tile wastes (CTW) in powder form to partially replace cement in lightweight foamed concrete was investigated with the aim to discover a greener construction material. Once the research outputs show that the ceramic tile dust can appropriately serve as a replacement, environmental impact on air, land, and water pollution can all be reduced. Three types of lightweight foamed concrete with 0%, 25%, and 50% ceramic tile wastes as partial cement replacement material were prepared with a target density of 1,200 kg/m³, namely, LFC-CTW0, LFC-CTW25, and LFC-CTW50, respectively. The effects of ceramic tile wastes on the engineering properties of lightweight foamed concrete were investigated. Concrete specimens were water-cured and tested for various mechanical properties at the concrete ages of 7, 28, and 56 days. Results from the lab experiments showed that the incorporation of 25% ceramic tile wastes into lightweight foamed concrete was more feasible than that of 50%. LFC-CTW25, which performed better than LFC-CTW0 for the splitting tensile strength test at day 56. The results for the compressive strength test, modulus of elasticity, and compressive toughness test showed a minor reduction after the incorporation of ceramic tile wastes. Based on the results, it can be concluded that it is feasible to use ceramic tile wastes up to 25% as partial cement replacement material to produce foamed concrete.

This research investigates the effect of pre-soaking treatment on plant-based aggregate using a wet grout binder to formulate a high-strength lightweight concrete (HSLWC). Surface modification utilising a novel grout soaking technique with various water-to-cement (w/c) ratios has indicated a new method of approach for the recent development of lightweight plant-based aggregate (LWPA). In this experiment, the fresh and hardened properties of modified LWPA lightweight concrete were assessed by verifying their workability, densities, compressive and split tensile strengths towards the modulus of elasticity. The results showed that pre-soaking plant-based lightweight aggregate (w/c: 0.6, 0.8, 1.0 and 1.2) slightly increased the density of the samples compared to untreated LWPA. The oven-dry density of treated and untreated LWPA is controlled in the range of HSLWC. The outcomes indicated that the workability of the surface-modified LWPA is significantly improved: up to 40% in 6 min for the (TDS)/0.6 sample compared to the original LWPA. The mechanical properties of the LWPA concrete with the surface modification method exhibit a substantial increment of compressive strength, split tensile strength and the modulus of elasticity; recorded at 22%, 26% and 34%, respectively. Significantly, the findings from this experiment reveal that the pre-soaking treatment method on LWPA is shown to be a highly recommended technique in improving interfacial bonding while maintaining its performance as one of the most promising solutions to improve the properties of lightweight concrete.

Proper cement-sand ratio and water content can provide excellent consistency and stability for lightweight foamed concrete. The aims of this study are to investigate the comprehensive optimisation design mix of lightweight foamed concrete with different cement-sand ratio and the effect of sand size and admixture towards the consistency and stability of the design mix. Silica fume as admixture was used to verify the improvements in the strength of the foamed concrete. Two types of foamed concrete were prepared, namely SC with sieved sand and UC with unsieved sand used in foamed concrete. Three different cement-sand ratios with different water content were tested for the above two types of foamed concrete for their compressive strength, consistency and stability. The results indicate that foamed concrete using sieved sand gained better consistency and stability. In addition, using silica fume in foamed concrete significantly improved the compressive strength with the highest strength at 27.12 MPa with 1700 kg/m ³ density.