Experimental Study. Expanders Concrete Performance Impact And Its Fuzzy Evaluation,

Expansion admixture of concrete can offset the tension-stress caused by drying shrinkage or temperature lowing of concrete. It has a good compensation to shrinkage, and can improve the anti-cracking and anti-penetrating performance of concrete. It is often added to concrete to produce expanding concrete or the anti-cracking and anti-penetrating concrete, which are widely used in such engineering as waterproofing, anti-penetrating, mending etc. The expansion admixture include at present sulphoaluminate such as UEA, EA-L etc), calcium oxide, and some composite expansion admixtures.In practical uses, the major performances of concrete are associated with the quantities, types and the service conditions of the expansion-admixture. The expansion admixtures of concrete available at present still have many shortcomings, such as the greater quantities required, the non-relevance between developments of concrete strength and durability and expanding speeds of expansion admixture, the evaluation of expanding effects, the DEF of AFt etc. Unfortunately, few achievements in these aspects have been obtained all over the world. The major performances of concrete and mortars, which are mixed with different quantities of expansion admixtures under the same mix proportions, are studied systematically and deeply in this work. Sulphoaluminate mixed with a type of new expanding component by use of the composite methods are studied in the laboratory, and some achievements have been obtained.The service conditions, the characteristics and the shortcomings of Expansion admixture in the concrete engineering are analyzed and summarized based on literatures, and the expanding mechanism of concrete is discussed. The effects of different types and quantities of expansion admixture on the major performances of concrete were experimentally studied. The crystal components, the quantities and their morphologies of hydration products such as AFt etc, are deeply analyzed by DTA and SEM. The major performances of all kinds of expansion admixtures according to the method of vaguely comprehensive evaluation based on many factors are evaluated. The result shows that the performances of the new expansion admixture are better than the others. The opinions concerning self-coordination associated the expanding ratio with the shrinkage ratio, expanding mechanism of AFt, study and development of the new high efficiency expansion admixture, are proposed.