Abstract
This study investigates the effect of curing regimes generally used for self-curing concretes (SC) on the engineering properties of normal strength concrete (NSC) and high-strength concrete (HSC). This study also examines the effect of exposing SC concrete to high temperatures up to 800 degrees C. This study applies five types of curing regimes. The first type is immersing concrete samples in a water tank. The second type is placing concrete samples in the air under lab conditions without curing. The third type is using different polyethylene glycol (PEG) doses by 1%, 2%, 3% and 4% of cement mass. The fourth type is using porous ceramic wastes aggregate (PCWA) as a course aggregate replacement by 10%, 15%, 20% and 25%. The fifth type is combining PEG doses by 1% and 2% with 10% of PCWA. Tests were conducted to investigate the mechanical properties of compressive, splitting, and flexural strength. The durability tests such as water absorption, water sorptivity, water permeability, chloride ion penetrability, carbonation depth and drying shrinkage were investigated. Weight loss and residual compressive strength tests were performed after exposure to high temperatures. The study recommends three self-curing regimes for NSC AND HSC based on a) compressive strength achieved, b) durability and c) mechanical and durability performance of concrete subjected to high temperatures. First: SC regime with a combination of 2% PEG and 10% PCWA achieved the maximum compressive strength of concrete that was reported to be 14.7% and 19.3% higher for NSC and HSC, respectively, compared to water immersion curing technique. Second: SC regime with a dose of 3% PEG (NCP3) achieved the optimum durability properties of NSC and HSC that were studied in this research. Third: SC regime, replacing coarse aggregate by PCWA up to 25%, that reduced the deleterious effects of high temperature on density loss and compressive strength.