低热硅酸盐水泥大坝混凝土施工关键技术研究

发布时间：2018-06-05 09:47

  本文选题：低热硅酸盐水泥 + 大坝混凝土　； 参考：《水力发电学报》2017年04期

【摘要】：低热硅酸盐水泥(简称低热水泥)混凝土早期强度发展缓慢,其施工工艺、施工进度、温控措施及其效果等方面与中热水泥混凝土有较大差异。为了论证高拱坝采用低热水泥混凝土的可行性,2013年6月在溪洛渡拱坝30号、31号坝段开展了低热水泥大坝混凝土施工关键技术研究,结果表明,与常规的中热硅酸盐水泥(简称中热水泥)混凝土相比,低热水泥混凝土冲毛时间延后16~20 h、拆模时间延后约24 h,但因大坝混凝土浇筑备仓时间通常在7~10 d左右,采用低热水泥混凝土对拱坝施工进度无影响;在浇筑温度、水管间距、一期通水水温和通水流量基本相同的条件下,拱坝混凝土最高温度采用低热水泥可比中热水泥降低4.6℃,封拱灌浆后的温度回升也较中热水泥混凝土低1.2℃;其他条件相同时,低热水泥混凝土的最大顺河向应力比中热水泥混凝土减小19%?65%,抗裂安全系数普遍提高且均大于2.0;拱坝低热水泥混凝土坝段横缝可以张开,接缝灌浆注入量与中热水泥混凝土坝段相近。截至目前,溪洛渡拱坝采用低热水泥大坝混凝土浇筑的30号、31号坝段尚未发现任何裂缝,低热水泥大坝混凝土施工质量和温控防裂效果优良。
[Abstract]:The early strength development of low-heat Portland cement (LHCC) concrete is slow, and its construction technology, construction schedule, temperature control measures and its effect are quite different from those of medium-hot cement concrete. In order to demonstrate the feasibility of using low heat cement concrete in high arch dam, the key technology of concrete construction of low heat cement dam in Xiluodu arch dam section 30 and 31 in June 2013 was studied. The results show that, Compared with the conventional medium heat Portland cement (medium heat cement) concrete, the blanking time of low heat cement concrete is delayed by 16 ~ 20 hours, and the time of mold removal is delayed by about 24 hours. However, the time of pouring storehouse of dam concrete is usually about 710 days. The use of low-heat cement concrete has no effect on the construction progress of arch dam, and the maximum temperature of concrete of arch dam is 4.6 鈩，

本文编号：1981556