Influence of various admixtures on energy absorption characteristics of foam concrete measured using one dimensional strain analysis test

Abstract

Foam concrete (FC) (a light weight cellular concrete) has recently clutched the interest of military engineering due to its special attributes such as cushioning behavior and energy absorption. However, only a very few investigations on the mechanical performance of FC and its energy absorption characteristics are reported in the literature. This study examines the effects of the addition of polypropylene fibres, fly ash (as filler replacement), and silica fume (as binder replacement) on fresh state features (stability and consistency), mechanical properties, and energy absorption characteristics. The individual and combination effects of various admixtures are studied experimentally. Hingot surfactant was used to produce FC mixes of target density 1000 kg/m3 with water to solid ratio of 0.3. Comparative analysis of various mixes showed that the fiber-reinforced fly ash mix showed the highest mechanical strength due to the bonding of fibres with the matrix, thus demonstrating synergistic behavior. Further, one-dimensional compression strain testing methodology was employed to study the energy absorption characteristics of FC. Experimental outcomes showed that the energy absorption values depend on two important components which are resistance against plastic yield, referred to as ductility, and resistance against damage referred to as the strength of the material. The incorporation of fibres enhanced the ductility of the specimen by acting as a toughening agent, whereas fly ash substitution contributed to enhancement of strength of the specimen due to pozzolanic and filler effects. Hence the combination mix with FA and PP (CMFP) showed significant improvement of 34.6% in energy absorption when compared to control mix.