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碱-集料反应是混凝土耐久性能之一,目前已引起世界各国有关专家的重视。发生碱-集料反应必须具备三个条件:活性集料、一定量的碱、水。随着建筑业的不断发展,集料的开采越来越广泛,水泥品种越来越多,外加剂的使用已相当普遍,高强度等级混凝土的应用已屡见不鲜。因此对碱-集料反应的研究已刻不容缓。 天津市建筑用水泥主要来源于天津、河北、山西等地。对几种不同品种水泥进行碱含量测定,其碱含量在0.656％～1.228％之间,均属于高碱水泥。高效减水剂、早强减水剂、防冻剂、防水剂的碱含量较高,无形中增加了每立米混凝土中的碱含量,高强度等级混凝土的应用,使单方混凝土中的碱含量增加。当每立米混凝
Alkali-aggregate reaction is one of the durability properties of concrete. At present, it has attracted the attention of experts from all over the world. The alkali-aggregate reaction must have three conditions: active aggregate, a certain amount of alkali, and water. With the continuous development of the construction industry, the mining of aggregates has become more and more extensive, cement varieties have become more and more, and the use of admixtures has become quite common. The application of high-strength grade concrete has become commonplace. Therefore, the study of the alkali-aggregate reaction has been brooked without delay. Tianjin’s construction cement mainly comes from Tianjin, Hebei, Shanxi and other places. Alkali content of several different types of cement was determined, and its alkali content was between 0.656% and 1.228%, all belonging to high alkali cement. The high alkali content of superplasticizer, early strength water reducer, antifreeze, and water repellent has virtually increased the alkali content in concrete per meter. The application of high-strength grade concrete increases the alkali content in single concrete. When coagulated per cubic meter