Hydration and durability of sulphate-resisting and slag cement blends in Caron's Lake water
Hydration and durability of sulphate-resisting and slag cement blends in Caron's Lake water
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DOI：
10.1016/j.cemconres.2004.06.038
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发表时间：
2005-08-01
影响因子：
11.4
通讯作者：
El Didamony, H
中科院分区：
文献类型：
--
作者：
Abd El Aziz, M;Abd El Aleem, S;El Didamony, H
硫酸盐和氯离子的侵蚀性问题一直是科学和技术研究的热点，因为这种侵蚀性是造成混凝土破坏的因素之一。氯化物的腐蚀作用是由于水合氯铝酸盐的形成，导致混凝土软化。硫酸盐离子可以与混凝土中的某些成分发生化学反应，生成水合硫铝酸盐和石膏，从而导致混凝土膨胀。本工作的目的是研究混合水泥(抗硫酸盐和矿渣水泥混合物)浆体和砂浆在Caron湖水中的水化和耐久性。制备了不同矿渣水泥配合比的抗硫酸盐水泥(SRC)，分别在自来水中浸泡3、7、28、90d。水泥砂浆的耐久性之后，样品在自来水中养护28天(零时间)，然后在Caron湖水中浸泡1、3、6、9和12个月。通过测定每个养护时间的抗压强度、游离石灰、蒸散水和非蒸散水、总氯离子和总硫酸盐含量来衡量水化性能。矿渣水泥(BFSC)掺量增加到30%时，SRC的总孔体积略有增加。游离石灰含量在浸泡的前几个月急剧下降，然后略有下降，一直持续到1年。在Caron湖水中浸泡的所有养护龄期，SRC和BFSC配制的水泥浆体的总氯离子和总硫酸盐的值较低，而仅含SRC的砂浆的抗压强度值低于所有混合水泥砂浆的抗压强度。关于使用70%SRC和30%矿渣水泥的有益结论和建议，可生产出高耐久的混合水泥。(C)2004爱思唯尔有限公司。保留所有权利。
The problem of aggressive attack of sulphate and chloride ions has been of considerable scientific and technological interest because this attack is one of the factors responsible for damage to concrete. The corrosive action of chlorides is due to the formation of chloroaluminate hydrates, which causes softening of concrete. Sulphate ions can enter into chemical reactions with certain constituents of concrete, producing sulphoaluminate hydrates and gypsum, which cause the expansion of concrete. The aim of the present work is to study the hydration and the durability of mixed cement (sulphate-resisting and slag cement blends) pastes and mortars in Caron's Lake water. Different mixes of sulphate-resisting cement (SRC) with various proportions of slag cement were prepared and immersed in tap water for 3, 7, 28 and 90 days. The durability of the cement mortars was followed by curing the samples in tap water for 28 days (zero time) then immersed in Caron's Lake water for 1, 3, 6, 9 and 12 months. The hydration behavior was measured by the determination of the compressive strength, free lime, evaporable and nonevaporable water, total chloride and total sulphate contents at each curing time. The increase of substitution of SRC with blast-furnace slag cement (BFSC) up to 30 % increases slightly the total pore volume. The free lime contents decrease sharply in the first months of immersion then slightly up to 1 year. The blended cement pastes made of SRC with BFSC up to 30 mass% have lower values of total chloride and total sulphate, while the mortars containing only SRC have lower values of compressive strength than those of all blended cement mortars at all curing ages of immersion under Caron's Lake water. Useful conclusions and recommendations concerning the use of 70 mass% of SRC with 30 mass% slag cement produces a highly durable mixed cement. (c) 2004 Elsevier Ltd. All rights reserved.