Experimental and numerical studies of impact behavior of fiber lightweight aggregate concrete

摘要

After the 9-11 attack, protection of iconic, strategic and public structures subjected to impact andexplosive loadings has been a major topic of research, which also involves with progressivecollapse, thermal effects, damage analysis and advanced material technologies. The demand forLight Weight Aggregate Concrete (LWAC) in many recent applications is increasing owing tothe fact that lower density of structural material leads to lower gravitational loading of structuresand consequently lower earthquake forces. Nevertheless, LWAC usually suffers from lowductility similar to other brittle materials. A remedy is to add fibers to increase the ductility andenergy absorption.As these lightweight constructions may be subjected to impact loadings during life timeperiod, investigating the impact behavior of concrete structures is necessary. A few studies wereperformed on impact behavior of normal fiber reinforced concrete. Nonetheless, there is noreport on impact behavior of fiber reinforced lightweight aggregate concrete.In this research, cylindrical fiber lightweight aggregate concrete samples with 150 mmdiameter and 60 mm thickness are exposed to low velocity impact load (according to thestandard of ACI 544-2R "impact test on fiber reinforced concrete") and compared with plainconcrete samples. Coarse pumice aggregates were used in concrete. Also, polypropylene wasutilized in mixtures proportion of concrete.In addition to experimental approach, a numerical simulation has been performed to analyzethe test specimens under impact loadings using the LS-DYNA finite element software.Comparison of numerical predictions with experimental results illustrates fairly good agreement.