and as a check to determine if sufficient materials areavailable to constructor complete a project. In general,the term bulk material refers to concrete, bituminouspaving materials, and mineral products, such as sand,gravel, or rock. A few examples of estimating thesematerials are described below.ConcreteEstimating the amount of concrete required for aproject consists of determining the volume (in cubicyards or, in many locations outside the United States, incubic meters) of the spaces that will be occupied by theconcrete. As an example, let’s look at figure 5-2. Thisfigure shows the foundation plan and a typicalfoundation detail for a small 20 foot by 32 foot building.As shown in the detail, the foundation is continuous andthe floor is a 4-inch-thick concrete slab. Our task is todetermine the amount of concrete that will be requiredfor the foundation and slab. Since in any concrete job acertain amount of concrete will be unavoidably lostduring placement, we will include a 10-percent wastefactor. You can find this waste factor listed in the P-405.Although we could proceed in various ways toestimate the amount of concrete that is required, an easymethod is tabulated as follows:Foundation wall:(32.00 ft x .67 ft x 2 fi) x 2 = 85.76 cu ft(18.67 ft x .67 ft x 2 ft) x 2 = 50.04 cu ftFooting:(33.33 ft x 2 ft x 1 ft) x 2 = 133.032 cu ft(17.33 ft x 2 ft x 1 ft) x 2 = 69.32 cu ftSlab:18.67 ft x 30.67 ft x .33 ft = 188.96 cu ft527.40 cu ftx 1.10 (10% waste)580.14 cu ft= 21 cu ydFrom the above tabulation, you can see that separateestimates were prepared for the foundation wall,footing, and slab. You can also see that both thefoundation wall and the footing were further subdividedbased on the length and width of the building; forexample, the foundation wall consists of two wallsmeasuring 32 feet long and two measuring 18 feet 8inches long (allowing for overlap at the foundationcorners). Then, the separate estimates were addedtogether, the waste factor was applied, and the finalcubic feet of concrete was converted to cubic yards.Now let’s see how much compacted fill will berequired for this job. For this example, we will assumethat the project specifications call for sand to be used asthe fill material.Figure 5-2 shows that the fill material is to be 8inches thick after compaction. Therefore, the volume ofthe compacted fill is 383.65 cubic feet. However, fromyour knowledge of soils, you know that compacted sandoccupies less volume than loose sand. Since the sand forthis project will be delivered to the jobsite in a loosecondition, a compaction factor must be applied.NAVFAC P-405 lists compaction factors for variousmaterials. For sand, the compaction factor listed is 1.17.So, the total amount of sand required for this project is383.65 x 1.17=448.87 cubic feet, or 16.6 cubic yards.Again, however, we know that a certain amount of sandwill be wasted. So, let’s increase the total by 10 percent.Now we need approximately 18 cubic yards of sand forthe job.Bituminous PavingAlthough not always, most bituminous pavingprojects that are accomplished by the Seabees usehot-mixed bituminous concrete that is purchased froma central plant. In this case, the job of estimating consistsof determining the compacted volume, in cubic feet, ofthe pavement. This volume is then multiplied by the unitweight of the mix, in pounds per cubic foot (pcf), andthe final result is converted to tons of mix required. Anequation for determining the required tons of mix canbe expressed as follows:Tons of mix =LxWxTxU W12 x 2000Where:L =W =T =UW =Length of paved area in feetWidth of paved area in feetCompacted thickness of the pavement ininchesUnit weight of the mix in pounds percubic footTo illustrate the use of this formula, let’s assumethat we are estimating a 2-inch-thick hot-mix5-7

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