Sulfate attack and embedded steel corrosion resistances of volcanic-aggregate concrete with fly ash and silica fume

Construction materials are increasingly on high demand in the developing world. The construction industry has a challenge of discovering, new  alternative construction materials to conventional materials which are locally available materials in environmentally friendly manner. The  experimental tests are conducted on volcanic concrete system to analyze its properties especially corrosion resistance potential for its applicability in construction. The major aim is to investigate its suitability and corrosion resistance potential especially when used in construction of structures with embedded steel. The test results of the material show that volcanic concrete system with 30% fly ash and 10% silica fume cementing materials is an alternative green construction material. Permeability properties are reduced by 8% and 24% with 30% fly ash and 10% silica fume respectively. Tests also indicate that Compressive strength, Corrosion potential and polarization resistance in volcanic concrete system with supplementing  cement materials has more potential to resist sulfate attack when compared with conventional volcanic concrete systems. The supplementary cementing materials (SCM) reduce the pore system and hence decrease the ingress of corrosive ions an  water in concrete. Corrosive ions, moisture and air would initiate corrosion to the embedded steel in concrete leading to reduced service life such structures. Key word: Supplementary Cementing Materials, Sulfate attack, volcanic concrete system, Granite powder, river sand, Corrosion of embedded steel