| Porous concrete is made by single size and blended aggregate gradations,in experimental work the porosity varies for different size of aggregates,it is difficult to get the exact same porosity with different gradations,more over the strength is governed by many factors which are coupled together such as aggregate content,paste volume and aggregates size.Monte Carlo simulations were carried out to study the effect of size of aggregates on the compressive strength of porous concrete by keeping the porosity and aggregate content constant by changing the aggregate sizes only.For the mesoscale study Porous concrete has been treated as heterogeneous composed of 4 phases i.e.aggregates,pores,mortar and interfacial transitional zone(ITZ).Shape of aggregates cannot be neglected and in most studies has been generated as circles or regular polygons but in present work convex polygons represent aggregates.Numerical concrete has been models by random take and place method in MATLAB,three different aggregate gradations have been generated(4.75-9.5 mm),(9.5-12.5 mm)and blended mix(4.75-12.5 mm).In two dimensional simulations the area fraction of aggregates has been kept 50 percent with 10 percent pores for all samples for as pore size follows Weibull distribution therefor pores the diameter have been generated using random Weibull number.Explicit finite element analysis have been performed by inserting zero thickness cohesive element,the results shows that the compressive strength of porous concrete unlike convention concrete increase with the decrease in size of aggregates and decrease with the increase in the size of the aggregates but is greater with blended aggregates for the same porosity. |
