The Effects of Temperature Curing on the Strength Development, Transport Properties, and Freeze-Thaw Resistance of Blast Furnace Slag Cement Mortars Modified with Nanosilica

Abstract

This investigation studies the effects of hot water and hot air curing on the strength development, transport properties, and freeze-thaw resistance of mortars incorporating low-heat blast furnace slag cement and nanosilica (NS). Mortar samples were prepared and stored in ambient conditions for 24 h. After demolding, mortar samples were subjected to two different hot curing methods: Hot water and hot air curing (40 °C and 60 °C) for 24 h. For comparison purposes, mortar reference mixes were prepared and cured in water and air at ambient conditions. Strength development (from 1 to 180 days), capillary water porosity, water sorptivity, and freeze-thaw resistance were tested after 180 days of curing. The experimental results showed that both curing regimes accelerate the strength development of mortars, especially in the first seven days of hydration. The highest early strengths were reported for mortars subjected to a temperature of 60 °C, followed by those cured at 40 °C. The hot water curing regime was found to be more suitable, as a result of more stable strength development. Similar findings were observed in regard to durability-related properties. It is worth noting that thermal curing can more efficiently increase strength in the presence of nanosilica, suggesting that NS is more effective in enhancing strength under thermal curing.

Frost Resistance and Pore Structure of Concrete Incorporated with Rubber Aggregates and Nano-SiO2

“…The frost resistance of concrete is usually described and characterized by mass loss and the relative dynamic modulus of elasticity (RDME) [ 24 ]. Figure 2 presents the loss ratios of mass and RDME of the designed concretes with rubber aggregates.…”

Effect of Nano-SiO2 on the Microstructure and Mechanical Properties of Concrete under High Temperature Conditions

“…The MIP method is widely used to describe porosity structure in porous materials, including cement-based composites [ 49 ]. It is used to analyze the problems regarding the durability of cement composites at high and low temperatures [ 26 , 50 ]. The results of the MIP tests are shown in Figure 11 .…”

“…However, the high content of NS admixture can cause a total porosity increase, which was observed in specimens C5 with the total porosity higher than that of the specimens without NS (14.3%). The tests on the cement mortars modified with NS [ 49 , 50 ] confirm that nanosilica not necessarily causes an increase of cement matrix porosity but significantly affects the porosity structure.…”

Nano-Modified Vibrocentrifuged Concrete with Granulated Blast Slag: The Relationship between Mechanical Properties and Micro-Structural Analysis

“…The issue of the durability of concretes and mortars based on slag has also received much attention [26,30,[32][33][34][35][36]. At the same time, these characteristics of solutions with the addition of DHS as frost resistance [30] and resistance to chlorides [34], sulfates [33], and various acids [26,32] were studied.…”

“…The effect of the hardening temperature on the concrete properties with the addition of ground granulated blast-furnace slag (GGBFS) was investigated in [17,28,30], in which an analysis of the dependence of properties on the formulations and hardening temperatures of concrete was conducted. In [17], an analysis is undertaken of the influence of the hardening temperature on the final strength of artificial stones consisting of 50% slag, 50% fly ash, and the alkaline additive NaOH (10 M).…”