J.Y. Zhao, Q.W. Yang* and C.F. Liang Pages 202 - 208 ( 7 )
Background: The cracking load is an important parameter in the design and testing of beam structures according to the recent patents. Compared to ordinary concrete, recycled aggregate concrete components are more prone to cracking.
Methods: In this paper, the calculation method and the size effect of the cracking load for the recycled aggregate concrete beam were studied. Four recycled aggregate concrete beams with different sizes were tested by the four-point bending experiment to obtain their cracking loads. According to the comparison of the tested values and the calculated values by two existing methods, it was found that the existing calculation methods are only suitable for small-sized beam specimens. The main reason for the calculation error lies in the fact that the existing calculation method does not consider the size effect of tensile strength of recycled aggregate concrete.
Results: It is very necessary to modify the existing formulas to calculate the cracking load more accurately for large-size beam specimens. Therefore, this paper presents an improved formula for the cracking load calculation by considering the size effect. The calculated results obtained by the proposed method are closer to the test values than those obtained by the original methods.
Conclusion: It has been shown that it is necessary and reasonable to consider the size effect in the calculation of the cracking load of the recycled aggregate concrete beam.
Recycled aggregate concrete, beam structure, cracking load, size effect, demolition, waste concrete.
Department of Civil Engineering, Shaoxing University, Shaoxing, 312000, Department of Civil Engineering, Shaoxing University, Shaoxing, 312000, Department of Civil Engineering, Shaoxing University, Shaoxing, 312000