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一、前言为了解决混凝土冬季施工问题,多年来,都用加热的方法使混凝土本身维持正温以继续硬化,但这增加工程造价,施工也较麻烦。为此我国曾推广过掺外加剂(冷混凝土)的方法,使混凝土能在负温下继续硬化。如五十年代普遍推广使用的CaCl_2和NaCl负温硬化外加剂,但是十几年的实践证明,氯盐加剧了钢筋锈蚀,因此掺大量氯盐的方法实际上已停止使用。此外,国外应用过的K_2CO_3和纸浆废液等负
I. INTRODUCTION In order to solve the concrete winter construction problem, for many years, the concrete itself is maintained at a positive temperature by heating to continue hardening, but this increases the construction cost and the construction is also more troublesome. To this end, China has promoted the method of adding admixtures (cold concrete), so that the concrete can continue to harden at negative temperatures. For example, CaCl 2 and NaCl negative temperature hardening additives commonly used in the 1950s have been popularized, but more than ten years of practice have proved that the use of chlorine salts has exacerbated the corrosion of steel bars. Therefore, the method of adding a large amount of chlorine salts has virtually ceased to be used. In addition, K_2CO_3 and pulp waste liquids applied abroad are negative