Construction Solutions LLC
PO Box 1334
Cedar Park, TX 78630
Gunite as herein specified is a trade name used to designate a mixture of Portland cement and sand thoroughly mixed dry, passed through a cement gun and conveyed by air through a flexible tube, hydrated at a nozzle at the end of such flexible tube and deposited by air pressure in its place of final repose.
Unless otherwise specified, all dry shotcrete (aka gunite) shall be mixed at the minimum in the proportions of 1 part cement to 5 parts of sand based on dry loose volume. Otherwise stated, the average compressive strength of gunite should be at an average of 2,500 P.S.I/ 17.24 MPa after 28 days of the gunite shoot. Gunite strength will equal or exceed 85% (2125 P.S.I.) of the design strength with and not less than 75% (1875 P.S.I) after 28 days. These are the set standards set by APSP (the Association of Pool and Spa Professionals) in the 3rd edition v3.3 of their Builders Manual for dry shotcrete for this region of the state and country.
Only Portland cement of American manufacture complying with the current issue of “Standard Specifications for Portland Cement,” A.S.T.M. C-150-67 shall be used. Type I Portland cement shall be used unless specified in the detailed specifications. Cement is purchased and transported from a third party vendor and not produced by Texan Gunite.
Fine aggregates shall consist of washed sand and shall be hard, dense, durable, clean, sharp and graded evenly from fine to coarse in accordance with the “Standard Specifications for Concrete Aggregates,” A.S.T.M. Designation: C33-67. It shall be free from organic matter and shall not contain more than 5% by weight of deleterious substances. Sand is purchased and transported from a third party vendor and not produced by Texan Gunite.
Water used for hydration at the nozzle shall be fit for drinking and shall be maintained at a uniform pressure which shall be at least 15 pounds per square inch above air pressure at the nozzle. Water is supplied by the client at the site of the project whether from the house itself (city or municipality), a water well, or a water truck. Water quality is important and can affect the overall quality and strength of the gunite.