Microstructure characterization of sustainable light weight concrete using trapped air additions

Abstract

Light-weight aggregate and trapped air additions (TAD) affect concrete performance and lead to the production of light-weight concrete (LWC). In this research, fourteen mixes were designed to study the effects of TAD type and content and pozzolanic material (PZ) type on the microstructure characterization of concrete. Aluminum powder (AP) and lightcrete (LC) were used as TAD with content equal to (0%, 0.25%, 0.50%, 0.57%). The PZ included silica fume (SF) and fly ash (FA) with content equal to 10% of the weight of cement. Tests were performed for compressive strength, density, SEM, EDS, XRD, and TGA/DTG. The results show that the compressive strength and density are reduced as TAD ratios are increased. On the other hand, the results of SEM and EDS showed that the production of calcium silicate hydrate (CSH) was reduced, but the pores and air voids were increased. However, the tests TGA/DTG performed showed that the hydration degree of the mix without TAD cement paste grew faster than the other mixes

Keywords

• light-weight concrete (lwc)
• trapped air additions (tad)
• pozzolanic materials (pz)
• compressive strength
• density
• microstructure