No abstract

Around 85 thousand tonnes of egg shell waste were yield in Malaysia at 2017, and when its utilization rate is low and not treated and disposed properly, it might result in environmental problem. By partially replacing cement with egg shell powder, the waste can be reduced and meanwhile reduce cement production that results in depletion of natural limestone and emission of carbon dioxide. Therefore, this study was carried out by aiming to mitigate the environmental issue by reducing eggshell wastes and pure cement production, and meanwhile, to promote the application of lightweight foamed concrete. The objective of this study is to investigate the effects on spread diameter, stability water absorption, initial surface absorption, sorptivity, and compressive strength of lightweight foamed concrete with fresh and hardened density of 1000 ± 50 kg/m3 and 1400 ± 50 kg/m3 when the cement is partially replaced by egg shell powder at replacement levels of 0%, 2.5%, 5%, 7.5%, and 10% by mass. The results showed that with incorporation of egg shell powder at all levels, the water absorption, initial surface absorption, sorptivity were improved, but spread diameter was reduced. Besides, stability of foam and compressive strength were improved in overall at replacement level of up to 7.5%. Therefore, it is feasible to use up to 7.5% egg shell powder as partial cement replacement material.

This study presents the effects of egg shell powder on lightweight foamed concrete when partially replace the cement. At 2017, 12235 million eggs were consumed and around 85 thousand tonnes of egg shell waste was the yield in Malaysia. The waste might result in an environmental problem if it is not reused properly. Besides, large cement production also results in carbon dioxide emission and depletion of natural limestone. Therefore, studies on effects of egg shell powder on properties of lightweight foamed concrete as partial replacement of cement is attractive to be carried out by aiming to promote the application of lightweight foamed concrete as well as to mitigate the environmental issue by reducing the number of eggshell wastes and pure cement production. The objective of this study is to investigate the effects on engineering properties of lightweight foamed concrete with a fresh density of 1200 ± 50 kg/m3 when the cement is partially replaced by egg shell powder at replacement levels of 0%, 2.5%, 5%, 7.5%, and 10% by mass. The properties of the lightweight foamed concrete studied included workability, stability, compressive strength, flexural strength, water absorption, and sorptivity. The results show that the replacement of egg shell powder reduces the spread diameter, stability, and sorptivity, and improve the compressive and flexural strengths at replacement level of up to 5%. The eggshell powder is feasible to be used as partial cement replacement material for the production of the masonry unit.

Abstract. Lightweight construction material, notably foamed concrete, had become more favourable to reduce building weight and cost, accelerate construction process, and ease handling of precast segment. Simultaneously, rapid development had result in price rising of conventional material and environmental issue due to abundant wastes, for instance steel slag. As a consequence, feasibility of steel slag to be incorporated in lightweight foamed concrete for both structural and nonstructural purpose is worth to be investigated. This paper is aimed to evaluate the effects of crushed steel slag, as partial replacement of sand with specific gradation, on performance of lightweight foamed concrete (LFC) with density of 1600 kg/m 3 to 1700 kg/m 3 in terms of compressive and tensile strengths. Different steel slag based LFCs were developed by replacing 0, 25, 50, 75 and 100% of steel slag for sand. Different water to cement ratios (w/c) and dosages of super-plasticizer (sp) were adopted to confirm certain workability, strength properties was then studied for ages of 7 and 28 days. The laboratory results showed that lightweight foamed concrete with incorporation of crushed steel slag has decreased strength; however it still achieves structural strength of 17 MPa when replacement level is less than 25% at density of 1600 kg/m 3 to 1700 kg/m 3 .

Nowadays, almost every industry needs to undergo green and sustainable industrial revolution due to pollutions like waste dumping and noise that deteriorating the environment. Therefore, feasibility study on application of eggshell waste as partial cement replacement in lightweight foamed concrete was conducted by aiming to solve environmental and acoustical issues, i.e. reduce eggshell waste and improve acoustic properties. In this study, compressive strength and acoustic properties of 1300 kg m-3 lightweight foamed concrete with and without 5% eggshell powder as partial cement replacement material were tested. Optimal water to cement ratio of 0.6 was obtained for acoustic properties test by comparing compressive strength result. The result shows that application eggshell powder has generally reduced 7 days compressive strength but improved 28 days compressive strength, and either improve or maintain acoustics properties, in which lightweight foamed concrete that containing eggshell powder has improved noise reduction coefficient at testing ages of 7, 28, and 90 days and improved sound transmission class at testing age of 56 and 90 days. Based on these results, 5% of eggshell powder is feasible to be incorporated into lightweight foamed concrete as partial cement replacement material for sound insulation and strength development purposes.