在桥面铺装层混凝土中掺用聚丙烯纤维能够增强其抗拉、抗折、抗渗、抗冲击能力，并起到阻裂增韧的作用。
The use of polypropylene fiber in concrete of the bridge deck paving can improve its tensile strength, bending strength, permeability strength, impact ductility, cracking resistance and toughness.
它采用轻韧的聚碳酸酯材料制作机身，速度快且敏捷。
The light and tough Polycarbonate body gives it exceptional speed and quickness.
分别给出了静止裂纹和定常扩展裂纹相变增韧的理论表达式。
The theoretical expressions of the toughening effect for both the stationary and steady - state growing crack are given respectively.
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