Design and Production of Concrete Kerbs for Pavement Construction Made with Saw Dust Ash as Partial Replacement of Cement

Abstract

This study evaluates the design and production of concrete Kerbs for pavement construction made with sawdust ash as partial replacement of cement. Fine aggregates used were obtained from a natural source from the Umudike River, Abia State. Sand passing the 4.75 mm sieve was used. The fine aggregate conforms to BS EN 13139, 2002 as the sand is free from contaminants. Coarse aggregates (uncrushed) used were obtained from Abakaliki, Ebonyi State. The Cement used to be the Ordinary Portland Cement (Dangote brand (42.5N)) that complies with the specifications NIS 444-1, 2003 and BS EN 197-1, 2000, bought from the market. Potable water from the tap in Civil Engineering Laboratory, Michael Okpara University of Agriculture, Umudike, was used for the curing of the cubes. This water conforms to the requirement of BS EN 1008-2002. Saw dust were obtained from timber shed at Umudike town, and was air-dried and then ashed by burning in an incinerator at temperatures generally bellow 650⁰C. The ash was then sieved and the bigger particles remained in the 600ℳm sieve were thrown away, however those passing the sieve were used for the research. No crushing or any exceptional action to advance the ash quality and increase its pozzolanic properties were applied as the researchers sought to use simple processes that can be easily simulated by local community residents. The concrete kerbs were produced with the use of concrete cubes mix design proportion of 1:2:4 was achieved. Fine aggregate was partially replaced with saw dust ash. Five (5) samples of 1,2,3,4 and 5 of 60 pieces of 150mm x 150mm cubes, the mix 1 were cast in cement only [100% OPC] which serves as the control mix, then sample 2,3,4 and 5 was cast with some percentage replacement of 0%, 5%, 10%, 15% and 20% of cement with saw dust ash respectively. The result showed that the compressive strength of the kerbs stones increased slightly with curing period and the amount of saw-dust ash (SDA) with early curing aging, but the strength improved significantly at the later curing aging, indicating a pozzolanic reaction. Only 5% saw dust ash replacement is adequate to achieve maximum strength gain and thus recommended for production of Concrete kerbs for pavement construction.