Copyright Goodheart-Willcox Co., Inc. Chapter 3 Tools and Equipment 39 and are about 1/8″ thick. Blades are made of very hard material, such as silicon carbide or industrial diamond. Most masonry saws can saw materials dry or wet. Water is used to cool the blade and eliminate dust. Water is pumped from the tray below the movable table where brick and block are positioned prior to cutting. The water flows over the top of the blade and returns back into the water tray to be pumped again. 3.2 Site Preparation Tools and Equipment Compaction of the subgrade is a very important step that needs to occur prior to concrete being ordered for deliv- ery. If the subgrade is not compacted sufficiently, the overlying concrete driveway, sidewalk, or other projects will crack or settle over time because the compaction process was not performed correctly. The following are examples of tools and equipment to aid masonry work- ers in performing an important step in site preparation. 3.2.1 Tampers, Packers, and Compactors Soil hand tampers are used to compact aggregate, sand, soil, or other materials during the time of backfilling around a foundation or structure. Hand tampers are used also in preparation for concrete to be placed in forms for sidewalks, patios, concrete floors, or a num- ber of other applications. See Figure 3‑33. Figure 3‑34 shows a tamping rammer compactor. It is used to compact materials, similar to a hand tam- per, but will perform the job more quickly. The device has a hammering effect when compacting the material. The compactor is smaller than other packing devices, which will allow it to get into tighter spaces like back- filling around a foundation. In a vibratory plate compactor, Figure 3‑35, the bot- tom plate vibrates to compact the material with the weight of the machine aiding in the compaction pro- cess. The primary use of this compactor is to prep sub- bases for footings, driveways, sidewalks, and basement floors. Safety Note A power masonry saw is a dangerous piece of equipment to operate. Safety glasses or goggles are required. A face shield should also be worn to protect from flying chips. Ear protection is mandatory because of the amount of noise created by sawing brick or block. When sawing materials dry, wear a respirator to protect from silica dust created by sawing. Marshalltown Company Figure 3‑33. Hand tamper has a cast iron base to add weight and strength to the tool. The handle is made of wood that can be replaced when needed. The base of the hand tamper is 8″ × 8″ but other sizes can be purchased. Allen Engineering Corporation Figure 3‑34. Tampering rammer compactor is powered by a 3 hp gasoline engine. The rammer hammers blows to the surface being compacted. It operates at 650 to 700 blows per minute (BPM).