A Study on bond strength of normal concrete to high volume fly ash concrete

Now-a-days the deterioration of concrete is further current due to numerous reasons like improper bonding, corrosion of steel, inferior quality of materials any as improper accomplishment. The deterioration of concrete finishes up in reduction in helpful strength of concrete therefore necessitates the adoption of correct repairing ways in which some repairing /strengthening techniques of concrete structures frequently involve adding new concrete to associate existing concrete 0.5. The bond performance between the existent and repair concretes plays a awfully important role on the powerfulness of this strengthening strategy.
Surface treatments like wire - brushing, sandblasting, water spouting, chipping, etc., unit typically adopted. The Bond strength at the interface depends on roughness of the substrate that successively depends on Cohesion and Friction at the interface.at intervals the gift study previous concrete substrates every at 450 angles with vertical and in addition the ash concrete as overlaid material were unreal to live the shear the parameters of the investigation embrace 1) totally utterly completely different grades of concrete substrate (M30 & M60) 2) Roughness condition at the interface (Smooth (as cast) &Rough (chipped indentations)) 3) The overlaid concrete with different percentages of cement replacement with ash (0%, twenty fifth and 50%)
4) Varying percentages of steel reinforcement resisting the shear at the interface (4 No's of 4mm military intelligence (0.502%) and four No's of 6mm military intelligence. The specimen adopted is additionally a customary prism size of 400mm X 100mm X 100mm.The take a look at conducted is „Slant Shear test‟ as per SB 6319 zero.5 5.From shear tests it totally was found that the bond strength between the 2 interfaces was accumulated for twenty fifth ash content in
overlaid concrete and reduced for five hundredth ash content in overlaid concrete all the same the roughness of the substrate. However, the magnitude of increase in bond strength relied on the roughness of the substrate. further the presence of Steel reinforcement (Substrate with no
treatment for the roughness at the interface) accumulated the bond strength at the interface. From the determined Bond strength at the interface it's tried to estimate the planning constant of Cohesion and magnificence constant of Friction at the interface between the normal concrete and the fly ash overlaid concrete