FATIGUE PROPERTIES OF BASIC MAGNESIUM SULFATE CEMENT REINFORCED CONCRETE BEAMS: BASED ON RESPONSE SURFACE METHODOLOGY

摘要

In order to study the fatigue properties of basic Magnesium Sulfate cement reinforced concrete beams, specimens of the basic magnesium sulfate cement (BMSC) and ordinary portland cement (PO?C) were in strength grade of C40 and C50 were prepared, respectively. Response surface methodology is applied to this study. The results show that under the fatigue load, the deflection value of the specimen decreases with the increase of the number of fatigue cycles. The fatigue cycle life of the BMSC specimens with higher strength grades is more than that of the PO?C specimens, and the higher the strength grade, the more obvious. Under the fatigue load, the development of the midspan deflection of the specimen showed an S- shaped trend, and the deflection in the BMSC specimen was smaller than that of the PO?C specimen. The spacing of the cracks in BMSC columns was smaller than that of PO?C columns because of the better bond performance between the reinforcing bars and the surrounding BMS concrete. But the crack widths of BMSC columns were close to the width of PO?C columns. It shows that the BMSC specimen has a high rigidity and good resistance to deformation.