Modulus of Elasticity (MOE)is a key parameter in reinforced concrete design.It represents the stressstrain relationship in the elastic range and is used in the prediction of concrete structures.Out of range estimation...Modulus of Elasticity (MOE)is a key parameter in reinforced concrete design.It represents the stressstrain relationship in the elastic range and is used in the prediction of concrete structures.Out of range estimation of MOE in the existing codes of practice strongly affect the design and performance of the concrete structures.This study includes: (a)evaluation and comparison of the existing analytical models to estimating the MOE in normal strength concrete,and (b)proposing and verifying a new model.In addition,a wide range of experimental databases and empirical models to estimate the MOE from compressive strength and density of concrete are evaluated to verification of the proposed model. The results show underestimation of MOE of conventional concrete in majority of the existing models.Also,considering the consistency between density and mechanical properties of concrete,the predicted MOE in the models including density effect,are more compatible with the experimental results.展开更多
Construction loading before the age of 28 d can have the most significant effects on the slabs, especially for multi-story structures. The changing properties of the young concrete complicate the prediction of service...Construction loading before the age of 28 d can have the most significant effects on the slabs, especially for multi-story structures. The changing properties of the young concrete complicate the prediction of serviceability design requirements also. An experimental investigation is performed on four simply supported Light-Weight Concrete （LWC） one-way slabs subjected to immediate loading at 14 d. Effects of aggregate type, loading levels and cracking moment together with the influences of ultimate moment capacity and service moment on the instantaneous deflection of slabs are studied. Comparison of the obtained results with predictions of existing models in the literature shows considerable differences between the recorded and estimated instantaneous deflection of LWC slabs. Based on sensitivity analysis of the effective parameters, a new equation is proposed and verified to predict the instantaneous deflection of LWC slabs subjected to loading at the age of 14 d.展开更多
文摘Modulus of Elasticity (MOE)is a key parameter in reinforced concrete design.It represents the stressstrain relationship in the elastic range and is used in the prediction of concrete structures.Out of range estimation of MOE in the existing codes of practice strongly affect the design and performance of the concrete structures.This study includes: (a)evaluation and comparison of the existing analytical models to estimating the MOE in normal strength concrete,and (b)proposing and verifying a new model.In addition,a wide range of experimental databases and empirical models to estimate the MOE from compressive strength and density of concrete are evaluated to verification of the proposed model. The results show underestimation of MOE of conventional concrete in majority of the existing models.Also,considering the consistency between density and mechanical properties of concrete,the predicted MOE in the models including density effect,are more compatible with the experimental results.
文摘Construction loading before the age of 28 d can have the most significant effects on the slabs, especially for multi-story structures. The changing properties of the young concrete complicate the prediction of serviceability design requirements also. An experimental investigation is performed on four simply supported Light-Weight Concrete （LWC） one-way slabs subjected to immediate loading at 14 d. Effects of aggregate type, loading levels and cracking moment together with the influences of ultimate moment capacity and service moment on the instantaneous deflection of slabs are studied. Comparison of the obtained results with predictions of existing models in the literature shows considerable differences between the recorded and estimated instantaneous deflection of LWC slabs. Based on sensitivity analysis of the effective parameters, a new equation is proposed and verified to predict the instantaneous deflection of LWC slabs subjected to loading at the age of 14 d.
