Performance of quaternary cement concrete with fly ash rice husk ash and limestone powder

Abstract

Blending of a large amount of waste materials such as Fly ash, Silica fume, Rice Husk Ash (RHA), Limestone Powder (LP) etc. is being done in large extents in the manufacture of cement and cementitious products. A lot of work has been done on replacement of cement with the above Supplementary Cementitious Materials (SCMs), which have shown good results with respect to strength and durability. The objectives of this study are to characterize the optimum percentage of SCMs fly ash, RHA and LP. The quaternary blending of cement with fly ash, RHA and LP was done, to meet the strength requirements, including compression, tension and flexure, along with standard durability tests for ascertaining the results by the microstructural properties of the cement matrix. Towards this objective, experiments were carried out in three phases as per the standard test procedures. In the first phase, physical properties, chemical properties and characterization of fly ash, RHA and LP were carried out. In the second phase, strength and durability tests were conducted on binary blending of cement with fly ash, to arrive at the optimum mix. In the third phase, strength, durability and microstructure studies were conducted on ternary (Cement, RHA and LP) and quaternary (Cement, fly ash, RHA and LP) blended cements. The strength tests include compressive strength, split tensile strength and flexure tests. The durability and corrosion tests include test for density, permeable voids, water absorption, Rapid Chloride ion Penetration Test (RCPT), Chloride diffusion coefficient test, Impressed voltage test, , Anodic polarization Technique (Harmlessness test), Linear Polarisation Resistance(LPR) Technique, A.C.Impedance measurements, Open Circuit Potential (OCP) measurements, Gravimetric weight loss determination and pH measurement. The microstructural studies include X-Ray Diffraction (XRD) Studies, Scanning Electron Microscope (SEM)-EDAX and Thermo Gravimetric/Differential Thermal Analysis (TG/DTA).