This paper presents an experimental study on the thermal properties of alkali-activated slag paste, mortar and concrete utilising seawater and sea sand exposed to elevated temperature. The thermal properties of paste and concrete utilising cement, fresh water and river sand were also investigated for comparison purpose. The samples were heated to different target temperatures up to 1000 °C at a heating rate of 5 °C/min, and tested both under hot and cooled conditions. The thermal properties, including temperature gradient, visual observation, mass loss, thermal strain and mechanical properties (i.e. strength, Young’s modulus and stress-strain curve) were investigated. X-ray CT scanning and scanning electron microscopy (SEM) were conducted to understand the macro/microscopic changes of the paste and concrete in response to heating. Degradation in mechanical properties of slag paste is attributed mainly to the cracks induced by temperature gradient, pore pressure and phase change. The degradation of concrete is caused by thermal mismatch between paste matrix and aggregates regardless of the use of cement or slag, freshwater or seawater, and river sand or sea sand.

本文介绍了利用海水和海砂暴露于高温下的碱活化矿渣糊，砂浆和混凝土的热性能的实验研究。为了进行比较，还研究了利用水泥，淡水和河砂的糊和混凝土的热性能。将样品以5°C / min的加热速率加热到高达1000°C的不同目标温度，并在热和冷条件下进行测试。研究了热性能，包括温度梯度，目测，质量损失，热应变和机械性能（即强度，杨氏模量和应力-应变曲线）。进行了X射线CT扫描和扫描电子显微镜（SEM），以了解糊状物和混凝土在受热后的宏观/微观变化。矿渣浆的机械性能下降主要归因于温度梯度，孔隙压力和相变引起的裂纹。混凝土的降解是由糊状基质和集料之间的热失配引起的，而与使用水泥或矿渣，淡水或海水以及河砂或海砂无关。