id	keyword
ap-6580	concrete
ap-6580	strength
ap-6580	rha
ap-6580	specimens
ap-6580	ash
ap-6580	materials
ap-6580	cement
ap-6580	addition
ap-6580	replacement
ap-6580	properties
ap-6580	doi:10.1016
ap-6580	water
ap-6580	rice