Engineering and Microstructures Characteristics of Low Calcium Fly Ash Based Geopolymer Concrete

This paper reports an experimental study on some mechanical properties and durability characteristics for geopolymer concrete. The mechanical properties were (compressive strength, splitting tensile strength and bonding strength). While the durability characteristics included (permeability, water absorption and exposure to sulphate attack). Also study in-depth microstructure of concrete by the SEM test. All these tests conducted for both geopolymer and normal concrete at 28 days, to show the difference in behavior for the tow concretes. Results show that the compressive strength for geopolymer concrete gain most of its strength at early age as compared with normal concrete, also the results indicate that the bond performance of geopolymer concrete higher than normal concrete by 18.7% and thus proves its application for construction. Geopolymer concrete have good durability comparison with normal concrete, it has shown less permeability, water absorption than normal concrete with high resistance to sulphate attack compared with normal concrete. In addition to that SEM test results show difference in microstructure between geopolymer and normal concret