Suitability of Recent Clays for Clay Bricks manufacturing within Nineveh Governorate

Abstract

Field surveying, engineering tests and laboratory test analysis have shown that some of the local soils available in Nineveh governorate are suitable for production of clay bricks satisfying class A, class B and class C according to Iraqi standard No.25 1988.These soils include recent floodplains belongs to Al-Gayyara (GA) and recent sediments belongs to Al- Rashidia (RA) location. GA soil used directly and without treatment by sand, while RA soil was treated with different percentages of sand (10%, 30% and 50%) in order to improve their physical, chemical and engineering properties.The engineering tests have shown that the properties of the fired samples are affected directly by both the firing temperature and sand percentage. It is noted that increasing the firing temperature from 1100 ᵒC to 1150 ᵒC increases the compressive strength of GA samples from 22.50 MPa to 61.59 MPa (about 3 times) while the compressive strength of RA samples treated with 10% of sand is increased from 34.73 MPa to 56.80 MPa. The water absorption of GA samples reduced from 17.05% to 13.05% when the firing temperature increased from 1100 ᵒC to 1150 ᵒC while the water absorption of RA samples treated by 10% sand reduced from 13.33% to 3.48% when the temperature increased from 1100 ᵒC to 1150 ᵒC. The optimum firing temperature and optimum sand content which give the highest compressive strength, lowest water absorption and minimum amount of cracks were 1100 ºC and 10% respectively for RA location, while the optimum firing temperature which give the highest compressive strength and lowest water absorption for GA location was 1150 ºC without any addition of sand.