Effect of Polypropylene Fibres on Strength and Plastic Shrinkage of High Volume Fly Ash Self Compacting Concrete

Abstract

Objectives: The present paper aims to test the influence of polypropylene fibre on plastic shrinkage and compressive strength of High Volume Fly Ash Self-Compacting Concrete (HVFA_SCC). Methods/Statistical Analysis: Six 150mm cubes and a slab of dimension 560mm×365mm×114mm were casted each for five mixes of HVFA_SCC with and without polypropylene fibres. The cementitious material (600 kg/m3) and water to powder ratio (0.325) were kept constant. The self-compacting concrete mixes had a cement replacement of 30%, 40%, 50%, 60%, and 70% of class F fly ash. The dosage of polypropylene fibres was 0.1% of total volume of concrete.Findings: Experimentationson these mixes were made to attain the fresh properties of concreteon viscosity, stability, filling and passing abilities. The compressive strength and plastic shrinkage properties were determined. Slump flow values on the mix blends were in the range of 650mm - 800mm and flow times were ranging from 2 to 4 sec. The HVFA_SCC mixes with polypropylene fibres had developed the twentyeight days compressive strengths ranging from 24.0 MPa to 46.0 MPa. Addition of polypropylene fibres in high volume fly ash self-compacting concrete had not shown any significant effect on the strength parameters but it had improved concrete resistance to plastic shrinkage by reducing sedimentation and bleeding due to increase in cohesion of mix. The control on bleed water resists the migration of the cementitious fines and the sand to the surface. The PFSCC60 has attained a twentyeight days Compressive strength of 30 MPa. Applications/Improvements: PFSCC60 has consumed only 40% cement by weight of the cementitious material proves to be economical and by reducing the emission of greenhouse gases found to be ecofriendly