Durability of Waste Metal Bottle Caps Aggregate Concrete
Egbe-Ngu Ntui Ogork 1 and Daud Gussau Haruna 2
1,2 Department of Civil Engineering
Bayero University, PMB 3011, Kano, Nigeria
Email: egbenguogork@yahoo.com1, harunagusau65@yahoo.com2
ABSTRACT
This paper assessed the effects of Waste Metal Bottle Caps (WMBC) aggregates on the durability characteristics of concrete. WMBC used were obtained from local drinking points in Kano, Nigeria. The WMBC were prepared with its edges folded with hammer and plier and characterized for use in concrete of 1:2:4 mix ratio and water cement ratio of 0.55 containing WMBC aggregates as partial substitute of granite aggregate of 0, 10, 20, 30, 40 and 50% respectively. A total of seventy two (72) number 100 mm x 100 mm x 100mm cubes of hardened concrete were tested for compressive strength at the age of 3, 7, 28, 56 days of curing in accordance with standard procedure. Crushed samples of the cubes of WMBC concrete from the compressive strength test at 28 days curing for the six mixes were weighed and exposed in 5 % concentration of sulphuric acid (H2SO4) medium and weight retained recorded at 7 days interval until the 28th day, to determine the resistance of WMBC concrete to sulphuric acid aggression. Also, eighteen number 100 mm x 100 mm x 100 mm cubes of WMBC concrete were tested for water absorption at 28 days curing. A total of thirty six number 100 mm x 100 mm x 100 mm cubes of WMBC concrete cured for 28 days were subjected to elevated temperature of 200 oC for 1 and 2 hours, respectively and were also tested for compressive strength. The results of the investigations showed that WMBC aggregates were predominantly of Fe2O3 (97.7 %), smooth but denser than normal aggregates. The compressive strength and water absorption of concrete containing WMBC aggregate decreased with increase in WMBC content. However, up to 30 % WMBC could be suitable for partial substitution of coarse aggregate in concrete in normal environment. The resistance of up to 20 % WMBC concrete exposed to sulphuric acid environment is similar to that of normal aggregate concrete and slightly lower for higher content of WMBC aggregates. WMBC concrete exposed to elevated temperature experienced higher compressive strength loss than that of concrete made with crushed granite aggregate. The compressive strength loss of WMBC concrete at elevated temperature range from 8.9 % to 22 % and 22 % to 39.1 %, as opposed to compressive strength loss of control samples of 2.9 % and 10.3 %, for 1 and 2 hours exposure respectively.
Keywords: WMBC, Aggregate, Concrete, Durability.
