Corrosion inhibiting admixture for corrosion prevention in small scale reinforced concrete structures
- Vol.95(4), April
- Thane ACC LTD 2021
- 38-51p.
This study analyses the influence of commercially available mixed inhibitor [sodium nitrite based water reducing and corrosion inhibiting admixture (WSNI)] and bipolar inhibitor [dual mechanism corrosion inhibiting admixture (BPI)] on the strength and durability performance of Portland Pozzolana Cement (PPC) and Portland Slag Cement (PSC) mortar. The strength (compressive, split tensile, flexural, and shear) and durability (water absorption, water sorptivity, chloride ion penetration and accelerated corrosion) tests were conducted on Portland Pozzolana Cement Mortar (PCM) and Portland Slag Cement Mortar (SLCM) with and without inhibitor as per the relevant standards. The mortar mix of 1:3 with workability 75 - 90% in flow test with inhibitor admixing at 1, 2 and 5% by weight of cement were adopted in all the tests. It is found to be that inhibitor incorporation did not influence the fresh mortar properties but had resulted in appreciable reduction of the water cement ratio. The addition of WSNI and BPI significantly increases the compressive strength at early ages but marginal improvement at 28 day. There is a significant improvement in flexural and shear strength (up to 30%) for inhibitor admixed mortar in certain dosages. Appreciable reduction in water absorption and chloride ion penetration; and improved tolerable limit for chlorides were also noticed for inhibitor admixed PCM and SLCM specimens. The addition of mixed inhibitor and bipolar inhibitor at 2% is recommended for use in small sector construction projects for enhanced corrosion prevention in Reinforced Concrete (RC) structures.