水在混凝土中的作用及对混凝土性能的影响

水是混凝土组成中必不可少的材料之一,在混凝土中起着重要的作用,例如提供混凝土拌合物浇注时的和易性,是混凝土中水泥水化所必须的成分.水对混凝土的性能起着重要影响.混凝土浇注后表面的泌出水对混凝土性能的影响有利有弊;水灰比决定着混凝土的强度;一些有害离子(如氯离子)是通过水向混凝土中渗入而进入混凝土中并对混凝土的性能产生不良影响,且有可能导致混凝土中的钢筋生锈;饱水混凝土在受冰冻时水结冰对混凝土产生膨胀压,使混凝土产生冻融损害,水的存在使混凝土更容易碳化,也使得混凝土中的碱骨料反应得以持续进行.本文从上述各方面综述了水在混凝土中所起的各种作用及其对混凝土各种性能所产生的影响.

TTHE ACTION OF WATER IN CONCRETE AND ITS EFFECT ON CONCRETE PROPERTY

Water is a necessary material in concrete.Water plays an important part in concrete.It provides workability for concrete mixture;it is a necessary composition for cement hydrate.Water has an important effect on concrete property.The bleeding water has an advantageous and adverse effect on concrete property.The water cement ratio decides concrete's strength.The water penetrating into concrete may bring in a lot of harmful ions(for example chlorine ion),which has a harmful effect on concrete property and may brings into reinforcement in concrete to rust.Ice is formed when the water saturated concrete is freezed and produces expansive pressure to concrete,the concrete is disserved.Water promotes concrete to more easily carbonate.Base Silica reaction can durably proceed when water is in the concrete.The action of water and its effect on concrete property are reviewed from above mentioned several problems in this paper.