TABLE OF CONTENTS Concrete construction consists essentially of six stages excavating, formwork, reinforcement, pouring, finishing, and curing. Work begins with material estimating, site preparation, and layout.
Small batches of concrete can be mixed at the job site, but for quantities of one cubic yard or more, it is usually more convenient to order ready-mix concrete delivered to the site. Ready-mix concrete is sold by the cubic yard, and most suppliers require a minimum order of one yard. The cost of ready-mix varies with the distance it must be hauled for delivery, the size of the order, unloading time, and type of mix. The construction drawings will give you the shape and dimensions needed for various concrete elements such as a slabs-on-grade, basement walls, footings, driveways, sidewalks, and so on. If small quantities of concrete are ordered from a ready-mix supplier, it will only be necessary to calculate the total quantity of concrete needed. If concrete is being mixed on site, it will also be necessary to calculate the quantity of each ingredient needed to produce the required volume of concrete.
To estimate the cubic yardage of concrete needed, first calculate the area in square feet, then use the graph in Figure 3-1 to find the volume of concrete needed. Locate the calculated square footage along the top of the graph. Then follow the vertical line down until it intersects the diagonal line for the required concrete thickness. Read horizontally to the right to find the volume...
