Read B.M Mapeo, Denny Tlhalefang, and Lekgowa Lesole
SHHA, Rehabilitation, Cracks, Exapansove Soils, Maintanance, House aesthics
This paper presents a case study of cracks and fractures in buildings in Lobatse in southeast Botswana on walls and floors of houses and on new roads. The worst cracking is on houses in Woodhall I and II townships built through the Self Help Housing Agency (SHHA) programme, but other areas in town are affected. The average crack or fracture width is 10 mm, while the mode is 6 mm with a maximum width of 64 mm. Cracks are oriented in two principal directions: NE-SW and NW- SE and large cracks trend NE-SW. The widths of the cracks were used to derive the severity and the rate of crack development because the severities of cracks ultimately affect the aesthetic appearance of the house, including its use and overall stability. All the visited homesteads in Woodhall I and II, more than 90% of them contained a cracked building, more than 85% of the cracks lengths were long; affecting the whole house and more than 20% of the cracks are classified as severe to very severe. Are the cracks caused by activities of far field stresses such as earthquakes, choice of building materials or is this a local phenomenon?