COMPARATIVE STUDY ON SELF-CURING CAPACITY AND MECHANICAL PROPERTIES OF LIGHT WEIGHT CONCRETE USING PUMICE AS A COARSE AGGREGATE AND NO-FINES CONCRETE

Abstract

Lightweight concrete is a type of concrete that has a lower density compared to conventional concrete, making it a popular choice for construction projects that require lighter and more durable materials. The use of lightweight aggregates, such as expanded clay, shale, or perlite, in the concrete mixture reduces its weight while maintaining its strength and durability. The properties of lightweight concrete, such as its thermal insulation, fire resistance, and acoustic performance, make it an attractive option in building construction, particularly in high-rise buildings and areas with seismic activities. Due to its effect on the cement's hydration, curing has a significant impact on the properties of hardened concrete; particularly its durability and strength. Any careless operation during curing will adversely affect the strength and durability of concrete. Self curing concrete is one of the special types of concrete used to reduce insufficient curing due to human neglect, water scarcity in dry places, and inaccessible constructions in difficult terrain. Therefore, the purpose of this study is to study and compare the self curing ability and mechanical properties of lightweight concrete using pumice as coarse aggregate and no-fines concrete. To achieve the objective of this research, two different lightweight concrete mixes having natural sand with pumice coarse aggregate and only cement with natural gravel were prepared for concrete properties tests. The mechanical properties tests, such as compressive strength, split tensile strength, and flexural strength were conducted. All specimens were subjected to air curing at ambient temperature without water for 7, 14, and 28 days. The results of the hardened properties of the mixtures show that concrete mixtures with pumice as a coarse aggregate have high self-curing capacity and compressive strength, split tensile strength, and flexural strength with the percentage increment of 2.63%, 5.01%, and 4.20% respectively between the 7th to 14th-day self curing period and 3.20%, 9.45% and 8.90% respectively between 14th to 28th-day self curing period than the lightweight no-fines concrete by a self-curing method. This study informs the potential of this method to reduce fresh water waste during the concrete curing process, save labor expenses for the subsequent curing activity, and reduce wasted time spent during cure or using other conventional curing methods.