Experimental Study On Flexural Fatigue Performance Of Rubberized Concrete

Normal concrete suffers brittle failure problem even in the condition of meeting its required strength, it is a hot topic that how to improve the brittle failure of concrete while ensure its strength. Studies reported that adding rubber powder into concrete is an important way to solve this problem.Rubberized concrete (RC) take the characteristics of rubber and normal concrete into together, its main features are as follows:lightweight, low elastic modulus, high hardness, high elongation, anti-cracking performance, superior energy absorption and high toughness. Other feathers include abrasion resistance, anti-aging properties, low shrinkage coefficient, low thermal expansion coefficient and so on. In addition, RC also has superior function in heat insulation and sound insulation. The fatigue properties of structure and member could be greatly enhanced if RC is applied. However, there are a few studies addressed on fatigue performance, mechanism of damage evolution, checking method of structure, engineering applications of RC. In this dissertation, the flexural fatigue performance of RC is studied in this paper by test, the investigated results can be listed as follows:(1) Based on C50 normal concrete, the rubber powder substituted the fine aggregate in volume in order to study the properties of modified concrete such as the weight, the density, the cubic compressive strength, axial compressive strength and flexural strength under the different contents of rubber powder. The volume content of rubber powder is 5%,10% and 15% respectively.(2) Take a study on the static and constant amplitude cyclic loading experiments of RC specimens. It holds that it is significant on the plastic feature of RC specimens. The static strain and dynamic strain of RC are longer than that of normal concrete. The fatigue life of RC is longer than that of normal concrete under the condition that the same stress levels, the greater of the rubber dosage, the greater of the fatigue life of concrete. The strain of RC experience variation in three stages under the condition that constant amplitude cyclic loading, the proportion of three stages is 10%,80% and 10% respectively.(3) The statistical analysis about the fatigue life of RC is performed, and then the distribution regulation of fatigue life is obtained. Besides, the p'-S-N curves with different failure probability and the fatigue strength of RC are provided. The double logarithm fatigue equations of RC are obtained accordingly. Meanwhile, the damage behavior of RC under fatigue loading was analyzed. The observed phenomenon and rules from the tests were explained rationally.