POWDERED BURNT BRICKS AS A POZZOLANA
Clay from the physical and chemical disintegration of igneous rock, weathering which is the shale and limestone etc. Depending on the composition nature of the parent rock, clay varies (Neville and Brooks 2002). Clay result from grains of different sizes, which include sand (5.0mm to 0.14mm), dust (0.14mm to 0.005mm) and clay less than 0.005mm (BS 812: part: 1991).
According to lea (1970) the properties of PBB as a replacement for neutral volcanic ash pozzolans. The PBB value as an addition of mortar lime to obtain hydraulic properties has been known for long. (Smeaton, 2002) carried out the experiments on the use of PBB as a pozzolans in connection with the building of bridge where mortar mix with about 1/3rd of PBB. Pozzolanic material in production of mortar and concrete for constructing water retaining structure, (Bagge, 1994).
Critically observed and link the development of properties of pozzolanic material (PBB) on burning with temperature at which water loss occurs (Fremy, 1999). Then (Potter, 1990) described PBB and OPC which consist pozzolaniic cement, he stated that over 500 tones were used in sea water construction and also fresh water. In rebuilding of sinner dam, as observed by (Potter, 1990) the masonry was set in cement composed or formed of 70 OPC and 30 percent PBB. Water tight mortar 1:4 (OPC: sand) mix was found to yield.
The properties of powdered burnt brick as a pozzolana
The result of physical properties test of this pozzolanic material is observed and also sand were used for the research are shown below
From above result, PBB has specific gravity of 2.54, specific gravity of the value gotten on PBB is compiled with BS 12:1991 which described or shown its range to be minimum of 2.20 and about 2.80 maximum, approved for pulverized fuel ash (Neville, 1992) and also similar to the values obtained by Oyetola and Abdullahi (2005).
The different detected in specific gravity of these material (PBB) may be as a result of difference in fine particles of the materials. Consequently, it may result to difference in weight. Finally, SDA is weightless followed by RHA. This is in line with the result reported by Sa’ad (2005) on different PBB samples.
The specific gravity of sand was observed to be 2.65. The value gotten reduced within the limit for natural aggregates that ranges from 2.6 – 2.7(Neville, 1981).670kg/m3 and 660kg/m3 were known to be the compacted bulk density of PBB.
By Taylor PBB value are less than that of OPC which is 1440kg/m3 this shows that they are weightless materials. 1600kg/m3 was observed to be the compacted bulk density of sand.
This value is almost equal to the range given for bulk density before excavation of sandy soil that ranges from 1650kg/m3 to 1850kg/m3 as presented by Jackson and Dahir (1998).
Workability test of PBB
The result of this test on every specimen sample describes that the slump for 100% OPC and of 10% replacement of PBB pozzolana was within the range of 6-10mm which shows low workability (ASTM, 1881: part 2: 1970). The result of the compacting factor test on all the paste is close to the range of 0.85-0.92 approved by (Ochard, 1973) for road and slab concrete. It was seen from the tests result that mixes 10% replacement of PBB have lower slump than that 100% OPC.
References
Alfred, B. S. (1911). Modern Brick making. London: Scott, Greenwood and son Press.
American Standard for Testing Method C 618-78: Specification for Strength Requirement of Pozzolanic Materials.
ASTMC 192-92 (1992) Test for the Time Setting for Hydraulic Cement in Cement in American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pp 19103, U.S.A.
ASTM C 618-78(1978). Specification for Pozzolana, ASTM 1916 Race Street, Philadelphia. Pa 19103, U.S.A.
Bagge, A. J. (1994). Manufactured aggregate, Quality Ash. Retrieved from www.uk.999.oy.uk on june 14, 2013.
Balkeme, A. A. (1992). Fly Ash as Addition to Concrete. International journal for institute of material and environmental research never lends 4 (2), 8-19.
Beeby, A. W. (1994). Concrete in the oceans, cracking and corrosion. Technical Report. No. 1. Cement and Concrete Association, 7(2), 1-75.
British Standard Institution. (1971). BS12; ordinary and Rapid hardening cement 389 cheswick High Reed, London.
British Standard Institution. (1973). BS 882; part2, method of sampling and testify of light weight aggregate for concrete (metric version). British standard institution, 389 cheswick High Road, London.
British Standard Institution. (1975). BS 812: part; method of sampling and testing minerals aggregate, sand and filters. British standard institution 389 cheswick High Rofel, London.
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