EFFECT OF IMPROPER CURING ON THE STRENGTH AND TRANSPORT PROPERTIES

ABSTRACT

Concrete structures are designed to be durable regardless of environmental conditions, leading to a growing demand for research on factors that promote durability while maintaining quality and minimizing costs. Supplementary cementitious materials (SCMs) have gained attention for their ability to react with cement and enhance its properties. RHA, an agriculturally based pozzolanic material, is a promising SCM. This project investigates the “effect of improper curing on the strength and transport properties of low-grade Rice Husk Ash (RHA) concrete. It aims to understand how various curing methods affect the compressive strength and other structural properties of a low-grade concrete, with target strength of 20MPa having Ordinary Portland Cement (OPC) partially replaced by weight with different percentages of RHA. The objective of this project was to design a concrete mix with a target mean strength of 20N/mm². The mix was prepared by partially replacing OPC with RHA at different percentages, and then the resulting concrete was cast into metallic cubes of dimensions 100mm x 100mm x 100mm in a laboratory. To evaluate the effect of different curing conditions on the concrete, three methods of curing were used, including immersion, open-air, and a combination of both. The samples were cured for varying periods of 3, 7, 14, and 28 days. The immersion curing method involved fully submerging the cubes in water for the entire curing period, while the open-air method kept the cubes in open air without water submergence. The combined method included 3 days of immersion in water, followed by low-humidity open-air curing. The study provides valuable insights into the properties of low-grade concrete mixes under different curing conditions, which could be beneficial for construction and engineering applications.