Solution Summary: Grout Delivery System
A grout delivery system is an engineering control than can help reduce musculoskeletal disorders (MSD) from manual material handling. The grout hog is a hopper that utilizes gravity to deliver grout into the masonry wall. This system allows grouting to be done by only two masonry workers, one who guides the hose to the block cell and the other who manuvers the forklift.
Gravity feed systems for grout delivery include the Grout Hog and the Blastcrete MasonMate. The grout hog consists of a hopper to hold grout, an auger, an eight foot dispensing hose, and an automatic shut-off valve. After the hopper is filled with grout, the hopper is lifted by forklift or crane above the worksite. A masonry worker controls the flow of grout by pinching the hose or with the shut-off valve. The hopper sits on a swivel base that allows 17 feet of wall to be reached without moving the forklift or crane. Approximately 3 to 4 cubic yards of grout can be delivered per 1/2 hour. Three models are available: 1) powered by forklift hydraulics, 2) gas-powered and 3) Uphill Grout Hog. The Uphill Grout Hog has an extension arm coming from the hopper that allows grout to be delivered to more challenging areas, such as interior walls. Also, workers avoid walking under the hopper when using the Uphill Grout Hog. Clean up of the Grout Hog takes less than 15 minutes.
Other grout delivery systems include a grout pump and grout bucketing (bucket brigade). Grout pumps have a hopper to mix grout and a hose to deliver the grout. Air or gasoline powered grout pumps are available, as well as smaller hand-operated pumps. Grout pumps are often used with grout bucketing. Bucketing is labor intensive and physically demanding for the masons, requiring heavy and repetitive lifting of buckets of grout.
Heavy lifting and carrying can cause low back disorders, such as muscle strain or a disc herniation (“slipped disc”), which is bulging of disc material possibly pressing on the spinal cord or nerves that go into the leg. The grout delivery system can help reduce heavying lifting and carrying by eliminating the need to manually handle and carry grout to the job site.
How Risks are Reduced:
Grout delivery systems, such as the Grout Hog, removes the need to lift heavy buckets of grout. Since the hoppers of grout are handled mechanically, with either a forklift or a crane, there is no need to manually lift or carry heavy buckets of grout repeatedly. High hand forces from holding a grout pump hose are also eliminated.
The Grout Hog is a delivery system that relieves the operator from lifting and supporting the weight of grout. Bucket handling is eliminated since the grout is fed into the block by gravity from the hopper. Reduced lifting reduces the risk for developing a musculoskeletal disorder of the back and shoulders. High hand forces are also eliminated. If grout pumps are used, masonry workers must exert high hand forces to hold and control the grout hose. If a grout bucketing is used, masonry workers must grip the handles of heavy buckets of grout. Use of grout delivery systems such as the Grout Hog allows the masonry worker to easily control the hose.
Effects on Productivity:
Grout delivery systems such as the Grout Hog allow grouting to be done with only two masonry workers: one to operate the forklift or crane, and one to guide the hose to the block cell. In contrast grout bucketing requires a bucket brigade of three or more masonry workers. Also, since the Grout Hog hose is shorter than the hose of a grout pump, it takes less time to clean the grout hog hose. Multiple grout hogs may be used simultaneously to increase productivity. Each grout hog requires its own forklift.
There is a new product called self-consolidating grout (SCG) which has a flowable consistency due to the addition of polycarboxilates (chemical admixtures) to the composition. SCG is reported to be better at filling spaces in the core and preventing the presence of voids, plus faster truck unloading, mix pumping and placement of group; these factors in turn can result in faster grouting of concrete masonry walls and improved labor efficiency. It can be used with any kind of small-line pump. SCG is delivery to the job site with a truck.
Dan Anton, PT, PhD, ATC – Eastern Washington University, Lauren Gant, MS, and Alysha Meyers, PhD – University of Iowa
- Masonry, Tile, Cement & Plaster
- Pour cement, mortar, plaster, or grout