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The Official Publication
of the Mason Contractors
Association of America
Mixers, Pumps and Delivery Systems
Mortar and Grout Delivery
An overview of equipment features that allow you to meet the challenges of proper mortar and grout delivery
On any masonry jobsite, contractors are faced with decisions on how to best manage their material production and delivery. Successful contractors consider details such as tools, labor, job size and material specifications to ensure an acceptable profit margin on each job. In fact, each of these details is affected by the available equipment on the job, such as mortar mixers, delivery systems and masonry grouting pumps. The right combination of equipment is essential to prepare mortar and grout to the required mix design, and then deliver it efficiently.
The mortar mixer is arguably the most common piece of equipment in the industry besides a trowel. Mixers have capacities from four cubic feet to 16 cubic feet. They typically are powered by a gasoline engine (about five to eight hp) or electric motor. Gasoline engines are the norm in the United States; however, electric motors are popular overseas. Most mixers are designed with wheels and towing hitch, which will satisfy many contractors’ needs. These “general use” designs are great for bricklayers, stone masons and some block contractors for batching mortar and dumping it into a wheelbarrow or tub.
In recent years manufacturers have offered innovations, such as hydraulic dump, skid mounting and adjustable heights. Hydraulic dump controls reduce labor and may be a necessity, when the drum is elevated beyond reach. Skid mounting eliminates the common issue that arises when wheels on the mixer get in the way of the wheel barrow or mud pan. The adjustable height of these mixers allows contractors to use them with delivery systems and grout pumps, which require higher discharge heights than the typical 22-inch dump height on the standard mortar mixer.
Mortar mixers are prevalent in the industry, so much so that they have become a commodity. To separate themselves from the pack, some manufacturers have focused on increased durability. Higher quality mortar mixers may include specifications for the gauge of steel used in the drum and engine cover, drum and grill weldments, engine type, mixer paddle design and strength, schedule pipe used in the tongue, type of mixer blade shaft, size of grating, frame strength, drive gears, drive system, belt mechanism, drum latch/lock system, leg design, tire and axle specs.
The gauge of steel can make a big difference when your crew starts beating the mixer to break away mortar. You do not want the sides of your mixer drum to cave in or bend under this type of abuse. Some mixers feature extra-long paddles to thoroughly mix material in the drum, minimizing waste. Other usability features such as reversing, starting mechanism and location of bearings are worth noting. The ability to reverse the direction of the paddles is essential to avoid plugs. An electric start engine can help you avoid eventual deterioration of the pull cord. Mixers with bearing housings on the outside of the drum greatly reduce the chance of material entering bearings when seals wear out.
The thought of comparing so many features may seem overwhelming at first, but you will be able to eliminate mixers from manufacturers who do not provide detailed specs at all. Then you will be able to choose among the remaining higher quality, durable mortar mixers.
Other unique mixer designs are worthy of consideration. One example is a skid steer attachment mixer, which features nine-cubic-foot capacity and receives its power from hydraulic lines connected to the skid steer. Another design combines a mixer with a delivery system, allowing you to batch and deliver grouts in large capacities up to 20 cubic feet. These systems reduce trips back and forth between a separate mixer and delivery system.
Masonry companies often take advantage of material silos to store large amounts of dry materials on the jobsite. Although a silo mixer seems like a large piece of equipment, it only takes up a small area, about eight by eight feet. This small footprint makes the silo an ideal choice for work in concentrated urban areas or any project with space limitations. They are used on large commercial jobs and smaller jobs as well. Benefits of silo systems can apply to any size job as long as contractors have a telehandler or large skid steer to load material.
Silos are available in capacities from 15 tons (10 super sacks) to 36 tons. Some designs are fully enclosed to help keep material dry and reduce freezing. Silos can be used with mortar mixers or silo mixer systems. Silo mixers attach to the outlet of the silo to offer a clean and predictable approach to mixing mortars and grouts onsite. The combination silo/mixer eliminates bag breaking and sand shoveling on the jobsite. It also takes cleanup time of traditional mixers out of the equation. The materials used with silos are pre-blended and the silo mixer is computerized, which ensures a consistent mixture to meet job specifications. These mixers also offer simplified operations, including electric power and simple garden hose thread (GHT) connections. Silo mixer outputs range from three to seven yards per hour.
Ready-mix deliveries can be a smart option for grouting walls over eight yards per hour. At higher production rates, contractors may need the continuous supply from ready mix to keep up with grouting equipment. Labor to mix onsite generally costs more than ordering from a ready-mix company. However, many jobsite situations will require stopping and starting or several smaller pours. In these cases, ready mix may not be the best option, due to the need to have the material ready at exact times, “short load” issues or waiting charges. If you need a large pour and you have flexibility in terms of timing, a ready-mix truck can be a solution.
After batching and mixing the mortar and grout, contractors need an efficient means of delivering it to the masonry structure. Traditionally, contractors have filled block by manually pouring material from buckets. Grout scoop products are available to help, somewhat, with the efficiency of using buckets. However, contractors can preserve the strength of their workers throughout the day and avoid injuries that can result from overstressing their physical abilities by taking advantage of grouting equipment.
Thankfully, manufactures have designed delivery systems and pumps specifically for mason contractors. Grout delivery systems use a gravity-fed approach to drop grout into the masonry structure. This equipment consists of a hopper, auger, flexible material chute and motor, typically powered by hydraulics from a skid steer or lift. Gas or electric power is optional. These units are elevated by forklift above the work area, and then material is placed via a flexible chute. This equipment can be operated with as few as two workers, includes swivel designs for ease of positioning over walls, and features heavy-duty gauge steel for durability.
Manufacturers also have engineered masonry grout pumps to meet contractors’ needs. These pumps are designed within a certain output range and address the need to process fine or coarse grouts. Each offer slightly different material valve systems and portability features. Grout pumps do not require a forklift, which can free up equipment for other uses. Manufactures of “concrete-masonry” pumps offer trailer units with production rates of 25 cubic yards per hour. However, on a typical block fill job, contractors may only need to fill six to 10 cubic yards – enough to keep up with a ready-mix truck or on-site mortar mixer. Many trailer pumps are able to process grouts with aggregates from 3/8- to 1/2-inch, but may not handle aggregates up to 3/4-inch. The ball-check material valves on these pumps limit the size of the aggregate.
Other “masonry grout pumps” meet output ranges for pumping fine and coarse grouts, while offering innovations in portability such as self-propulsion, fork slots and lifting lugs. These pumps feature swing-tube material valves that process aggregates up to 3/4-inch. This is an advantage for contractors who tend to purchase less expensive coarse grouts. Masonry grout pumps can deliver grout as high as 100 feet (eight to nine stories) to meet wall grouting needs. Mounted on four wheels with hydraulic drive systems, these pumps are positioned on the jobsite as needed. Like gravity-fed delivery systems, masonry grout pumps require as few as two workers – one to start and stop the pump and another to hold a masonry wall hook (180-degree pipe bend) connected to the end of the grouting hose. Setup and cleanup time is about 20 minutes each.
Contractors who have smaller runs of CMUs and more frequent stopping and starting may use an entry-level masonry grout pump. These designs also are self-propelled, have outputs in the five- to seven-yard range and can handle fine grouts. For powering from the skid steer, hydraulic powered/skid mount grout pumps are available. For enclosed or indoor jobs, an LP gas-powered unit may be a good option. Loading heights on masonry grout pumps and grout delivery systems are on the high side (about 32 to 49 inches), so tow-behind mortar mixers are not compatible. Mortar mixers with telescoping legs, silo mixers and ready-mix deliveries are better complements to pumps or delivery systems.
Another advantage can be realized in the use of a grout pump. Traditionally, mortar is loaded into tubs or troughs then delivered via forklift to masons located on scaffolding. However, grout pumps are used to fill mortar tubs by hoisting mortar up to the scaffolds. This may be an advantage, depending on the logistics of the job.
These concrete trailer pumps might be a good option if you want to diversify into other areas beyond traditional masonry work, such as general concrete pumping, slab pouring, concrete lifting or shotcrete. On the opposite side of the spectrum, small grout pumps are available for low-volume grouting projects such as void-filling repairs to existing masonry structures. These pumps are typically hand operated or powered by air compressors and are designed for flowable grouts with no aggregates.
Be aware of the quality of any mixer, pump or delivery system that you intend to purchase, and do your homework. Pay attention to specifications and make comparisons wisely. If you feel it is important to only buy American made products, be sure to ask where the equipment is manufactured and where the company headquarters are located. Some U.S. companies have foreign production, and some foreign companies have domestic U.S. production. Large manufacturers have been sold to foreign companies in recent years. Luckily, the masonry industry has dedicated U.S.-owned manufacturing companies that follow your needs closely.
The next time you think there must be a better way, you are probably right. Check out your options, and you will find that the combination of the right masonry equipment can meet your next challenge, exceed your expectations and ensure your success.
|Last Updated on Friday, 06 September 2013 17:23|