Investigation on Behavior of Spalling Resistance of Ultra-High Strength Concrete under Severe Enviro

• 作 者: BeiSUN;ZhixiangLIN;ZhiweiGUI;
• 机 构: State Key Laboratory of Green Building Materials, China Building Materials Academy, 100024, China
• 出 处: The 14th International Congress on the Chemistry of Cement (
• 发表日期: 2015年期

　　Experimental investigation on the effects of fiber types, dosage and length on both explosive spalling of ultra-high strength concrete after exposure to severe high temperatures environment was presented.The mechanism of spalling resistance of ultra-high strength concrete was examined by thermal analyzer, X-ray diffraction and scanning electron microscope.The results indicated that the burst time can be extended but the spalling is not siginificantly affected by the addition of steel fiber.The spalling resistance can be improved with polypropylene(PP) fiber or PP and steel fiber.The ultra-high strength concrete mixed with PP fiber at a dosage 0.20 volume percent shows excellent spalling resistance.The resistance to explosive spalling of the concrete will be enhanced with 12 or 19 mm length PP fibers.PP fiber can improve the spalling resistance of the ultra-high strength concrete mainly due to the tubular channels from external to internal formed by PP fiber melted, in the second place, the increasing of the capillary porosity caused by the dehydration of hydration products.Both of these connect with each other, which can provide the channel to release the internal stress and relieve internal vapor pressure.