civil engineering-->>Planning and Site Preparation for Concrete

Planning and Site Preparation for Concrete  CONCRETE PLANNING  The most important step in placing concrete is planning. Always plan every step before any concrete is delivered. Proper planning avoids delays, wastage, segregation and problems which develop from these. Proper concrete planning also eliminates problems of Delay, Segregation and Wastage. Safety Workers on the site should always wear protective clothing, strong boots and, if required, helmets or eye protection. Always avoid direct contact with cement and never kneel in or touch the concrete mix directly. Wear gloves or use barrier creams. Ensure that anyone using heavy equipment, such as screeds or vibrators, has been properly trained. The following steps should be taken before any concrete is placed:
Measurement Measure and stake out the area to be concreted and consider how thick the slab must be. The thickness will depend on the weight the concrete must carry (ie driveway carries the weight of a car and needs to be thicker than a garden path). The Finishing Level Once the thickness of concrete has been established, work out where the concrete will finish. Concrete cannot finish too high against steps or the external house wall and should not cover any part of weepholes in the wall.The finishing level shows how much digging or excavation  must be done.Pavements must grade away from buildings and boundaries. Steps (Stairs): Steps must have even risers. Excavation The ground should be excavated as deep as is required by the finishing levels. Any roots or grass must be dug out until there is firm soil to place on.Always dig the hole wider than needed to allow for the formwork. Try to keep the edges and corners square.