Mechanical and Thermal Properties of Sustainable Low-Heat High-Performance Concrete

One of the main drawbacks of utilizing mass concrete is the high amount of heat produced during the hydration of cementitious materials. Low-heat high-performance concrete (LHHPC) is a special type of concrete with low Portland cement content and low heat of hydration. The main aim of this research is to experimentally explore the potential use of blast furnace cement (CEM III) and fly ash (FA) in LHHPC. CEM III is a type of cement with low heat of hydration. FA was used at various dosages, namely 10%, 20%, 30%, and 40%, as a partial replacement of CEM III for producing more sustainable LHHPC. The mechanical and micro-structural characteristics of the LHHPC mixes were investigated. In addition, the concrete thermal conductivity and heat of hydration were predicted and compared using ANSYS finite element software. The experimental results showed that 40% FA as a CEM III partial replacement decreased the heat of hydration in LHHPC by 38.7%. In addition, the produced LHHPC showed low thermal conductivity, which indicates a decrease in early-age cracks. The produced LHHPC showed a constant compressive strength of 90 days compared with the corresponding 28-day compressive strength. The experimental results were supported by scanning electron microscope (SEM) analysis and the numerical analysis for the LHHPC. The 3D finite element model provided accurate predictions for temperature distribution. The results of this research indicated that FA and CEM III can successfully produce LHHPC with adequate strength and low heat of hydration.

Automated summary

This research explores the potential use of blast furnace cement and fly ash in low-heat high-performance concrete (LHHPC) through experimentation. The characteristics of LHHPC, including mechanical and micro-structural properties, were investigated. The results show that 40% fly ash as a partial replacement of blast furnace cement reduces the heat of hydration in LHHPC and exhibits low thermal conductivity and constant compressive strength.