Influence of Curing Conditions on Properties of Normal and High Strength Concrete with and without Pre-Wetted Lightweight Aggregates

Abstract

This paper presents the results of an experimental study conducted to evaluate the effect of curing conditions on the properties of normal and high strength concrete (NSC and HSC) with and without pre-wetted lightweight aggregates (LWAs). Cylinder specimens were drilled out from square concrete slabs subjected to four curing regimes (i.e. standard, water, natural and sealed curing) respectively, and then tested to obtain the compressive strength after 60 days. Three discs cut along the height direction of cylinder specimens (top, middle and bottom) were used to orderly measure the ultrasonic pulse velocity (UPV), open porosity, water absorption and splitting tensile strength. Afterwards, the comprehensive evaluation index, i.e. relative curing efficiency (RCE), was proposed based on the testing results above to quantitatively assess the effect of curing conditions on the physical properties of concrete. The experimental results indicat-ed that curing conditions significantly influence the strengths and durability-related properties of NSC and HSC. The linear correlation can be obtained between sorptivity and open porosity of concrete under various curing conditions. Furthermore, in terms of the RCE analysis, the durability-related properties are more sensitive to the curing conditions than strengths for NSC and HSC.