Author(s)

C. Citto, A. E. Geister & D. W. Harvey

Abstract

For almost two decades, compatible injected fill (CIF) grouts have been used in the restoration and repair of historic masonry structures. CIF materials are installed using a low-pressure injection process and often serve the dual purposes of structural strengthening and enhancement of moisture resistance. In the past, improved weather resistance was primarily the result of the CIF material filling voids in collar, head, and bed joints through which moisture could penetrate. However, the CIF materials were not specifically formulated for moisture resistance. The weather resistance of CIF installations could be significantly improved by increasing the water repellency of the CIF material. However, if this innovation comes at the expense of significant changes to other material properties, it may not be a viable approach. This paper presents the ability of injected CIF material to improve the moisture resistance of masonry walls through a series of water penetration test results, and also describes a comparative study of CIF material properties in formulations with and without integral water repellent (IWR) admixture. Material properties relevant to typical CIF installations were evaluated using standard laboratory test procedures. Samples were tested for plastic properties, compressive strength, flexural bond strength, shear bond strength, vapor permeability, and water repellency. Tested samples used the same proprietary blend of cementitious materials, aggregate, and admixtures. The effects of IWR on material properties are discussed as well as overall feasibility of IWR admixtures in CIF materials. Keywords: building envelope, CIF, grout injection, integral water repellent, masonry walls, moisture resistance, water penetration, water testing.

Keywords

building envelope, CIF, grout injection, integral water repellent, masonry walls, moisture resistance, water penetration, water testing