In this study, we determinated the dynamic changing of soluble sugar, total nitrogen and malondialdehyde, so t㏊t found out their relationships with cold resistance. The result indicates: the content of soluble sugar and total nitrogen increased from late autumn and early winter, and kept higher level during the entire winter, then decreased in regreen time in the next spring. The content of malondialdehyde was high in Sep., then decreased gradually and reached the minimum in Jan., thereafter the content of malondialdehyde represented increasing trend.

Four shear-deficient reinforced concrete (RC) beam specimens with different shear span ratios were tested using a well-instrumented drop-weight impact machine to gain a better understanding of the effect of shear span ratio on impact behavior of RC beams strengthened with carbon fibre reinforced polymer (CFRP). The results demonstrated that the shear span ratio could change the failure modes for strengthened specimens and also affect the impact resistance.

This study is focused on three-dimensional nonlinear finite element analysis of reinforced concrete (RC) beams strengthened with carbon fiber reinforced polymer (CFRP) strips under impact loading. The validity of the model was assessed through the comparison with experimental results obtained from drop-weight impact tests of the authors. The well agreement proves the feasibility of the proposed numerical analysis method.