Gage Behunin, a masonry contractor and leader in the use of Sarabond, was driven out of business when a this high-chloride mortar failed. Behunin studied the masonry construction process to see how it could be improved. He discovered that bricklayers were spending most of their time leveling and plumbing wall, spreading mortar, and cleaning up rather than placing brick or block. He thought he could eliminate or at least minimize these activities in three ways:
- Providing a grid to lay against would minimize leveling and plumbing.
- Pumping mortar directly onto the units would eliminate trowel application.
- Using a thinset mortar to fill without protruding would optimize the amount of mortar used.
First he developed a chamfered block, an alignment grid made of 170-pound perforated aluminum panels, and a system to align the panels. Then he worked on a special cementitious mortar to be used in a pressurized system.
Masons lay the first course. The block at the high spot may have a very thin joint while the lowest brick or block may have a 1-inch joint. This critical course is allowed to set for a few minutes. Masons continue without levels or trowels, using a dual-nozzle wand to place two thin beads of mortar on top of the first course. Then they start laying the second course. The alignment grid alone ensures that the wall is plumb, and the thin mortar bed ensures that each successive course is as level as the one below.
In a shop demonstration, Behunin and two helpers were able to construct a 12-foot long, 4-foot high section of wall from scratch in less than an hour. In the field, the rate of construction would be expected to increase where it would outpace conventional construction methods.
Testing showed the mortar had a compressive strength of over 3500 psi and a bond strength of 150 psi. Moisture penetration tests found very low flow rates. Plumb and levelness were all with prescribed tolerances. Mortar fins were minimal.
So far, two projects using this system are a basement foundation and an office building near Denver. Others are being planned.
This system is one new way things can be done faster and with fewer skills. Gage Behunin continues to innovate and push the bounds of masonry construction.