Influence of curing period on some mechanical and durability-related properties of limestone powder concrete

Abstract

This study investigates the influence of curing periods on the mechanical and durability-related properties of limestone powder concrete, focusing on the potential of limestone as a sustainable alternative to traditional materials, primarily cement. The research explores the effects of varying cement replacement percentages (30-55%) and curing durations (1, 3, 7, 14, and 28 days) on concrete properties such as compressive strength, flexural strength, water permeability, and resistance to chloride ingress. The limestone fineness was also tested using two powders from the same chemical composition, but different particles size. Results indicate that longer curing periods generally enhance concrete performance, but not in all cases. The greatest benefits of extending the curing period was observed in the case of water penetration depth, so the average difference between 1 and 28 days curing was about 50%. Flexural strength also saw a substantial increase of up to 24% over the same curing period. However, increasing the curing period from 7 to 28 days resulted in an unexpected average reduction in concrete compressive strength of 13%. Despite previous results, a positive impact of a higher limestone powder content was observed in all cases, except for resistance to chloride penetration. Concretes that contained limestone powder had a significantly lower (as much as 186%) resistance to chloride penetration, compared to the reference (with the highest dispersion of results). The study found no significant influence of limestone particle size on concrete properties.