Effect of curing conditions during the first 24 hours after casting on the properties of mortar mixtures

Abstract

As it is well known, the curing method directly affects many properties of cementitious composites. In previous studies, the effect of different curing conditions on the properties of the cementitious systems has been generally investigated in the period after first 24 hours after casting. However, there are not many studies in the literature related to the effects of curing conditions on the specimens kept in mold during 24 hours after casting. In this study, strength development, ultrasonic pulse velocity (UPV) and water absorption capacity of mortar specimens subjected to steam-curing at different temperatures during keeping in mold for the first 24 hours after production were compared. In this regard, all mortar specimens were exposed to curing in a steam-curing cabin at 95% constant relative humidity (RH) under 5 different temperatures such as 20, 35, 50, 65 and 80˚C for the first 24 hours after the specimens were placed into the molds. Afterwards, the specimens were removed from the molds and cured in water conformed to the standard until the testing day. In this context, the water-cement ratio, sand-binder and slump-flow value of all mortar mixtures were kept constant as 0.485, 2.75, 25±2 cm, respectively. As a result, the application of steam-curing at high temperature for the first 24 hours positively affected the 1-day compressive strength and UPV values of the mixtures, while the 3,7 and 28-day compressive strength, UPV values and the 28-day water absorption capacity of mixtures were adversely affected.

Influence of hemp shiv, cement, and water content on the properties of lightweight hemp composites produced using different sizes of hemp shiv

“…In addition, strength gain was about 69 %, 34 %, 44 % for samples produced using fine, medium, and coarse hemp shiv aggregates with the increase of H:W ratio from 2.5 to 3.0, respectively. These might be as a result of decreasing water content of mixtures with the increase of H:W ratio, consistent with the prior literature (Mardani-Aghabaglou et al, 2020;Singh et al, 2015).…”

Mechanical properties, durability performance and interlayer adhesion of 3DPC mixtures: A state‐of‐the‐art review

“…It was emphasized that this concern was caused by the main factors such as not using formwork 83 and lack of curing process in 3DPC samples. It was reported that these parameters accelerate shrinkage and consequently increase the risk of cracking 84–86 . As it is known, plastic shrinkage is observed in cases where the evaporation rate is higher than the bleeding rate and causes shallow cracks on the surface 87,88 .…”

“…It was reported that these parameters accelerate shrinkage and consequently increase the risk of cracking. [84][85][86] As it is known, plastic shrinkage is observed in cases where the evaporation rate is higher than the bleeding rate and causes shallow cracks on the surface. 87,88 Compared to 3DPC mixtures, it is expected that the evaporation of pore water will be delayed and the severity of plastic shrinkage will be less as a result of the use of formwork and curing in conventional concretes.…”

Influence of Initial Temperature of Fresh Concrete on Compressive Strength of Concrete

“…Curing temperature histories affects the strength development of high strength concrete as well as normal concrete [3]. Therefore, the curing condition in the initial stage, especially fresh concrete temperature affects the rate of compressive strength development [4][5]. Several methods can be used to reduce the initial temperature of fresh concrete, such as: using chilled water, ice, chilled air, liquid nitrogen, and aggregate cooling.…”