A STRENGTH CRITERION FOR LIGHTWEIHT AGGREGATE CONCRETE BASED ON WARHEAD YIELD

Experiments show that lightweight aggregate (LWA) concrete and normal concrete have different mechanical properties and failure rules under multi-axial stress. Consequently, the strength criteria for normal concrete do not apply to LWA concrete. Considering the similar failure feature of LWA concrete with geomaterials, a continuum, smooth and closed warhead type strength criterion for LWA concrete was established. The criterion adjusted the warhead type yield function of geomaterials for meridian equation and selected the elliptic curve of the William-Warnke model for the π-plane shape function. The criterion overcame the unsmooth disadvantage of the parabolic-type strength criterion and the conservatism of elliptic strength criterion under high hydrostatic pressure. It can better describe the geometrical characteristics of the LWA concrete. The strength criterion was quantified by using the least square method. Additionally, the rationality of the suggested warhead-type strength criterion was verified by comparing with experimental data.