两类合成纤维在混凝土中的作用及使用效果(下)

Function of two groups of synthetic fibres in concrete and their efficacy

按合成纤维在混凝土中所起的作用,可分为两大类别,即防裂纤维与増韧纤维。前者主要用于防止或减少混凝土的早期收缩裂缝并降低裂缝的尺度,有助于降低混凝土的渗透性与提高抗反复冻融性。后者主要用于提高混凝土的变形能力,有助于减少混凝土的干缩裂缝、增进混凝土的韧性、抗冲击性与抗疲劳性。二者均起着次要增强材的作用。作者分别论述了这两类纤维在混凝土中的作用机制,对混凝土物理、力学性能与耐久性的影响及使用效果。

According to the function of synthetic fibres in concrete they can be classified to two groups, i.e. crack arrest fibre and toughen fibre. The former is mainly used for preventing or reducing the shrinkage cracks of concrete at early age and reducing crack sizes, thus it helps concrete to decrease permeability and increase freeze-thaw resistance. The latter is mainly used for improving the deformation capacity of concrete, thus it helps concrete to reduce dry shrinkage, increase toughness,impact resistance and fatigue resistance. Both of these fibres play the role of secondary reinforcement. The author expounds function mechanism in concrete, influence on physical properties, mechanical properties and durability of concrete, and use effi cacy for each synthetic fibre group, respectively.