New Specification for Permeability-Reducing Admixtures for Concrete
1. Scope
1. Scope
1.1 This specification covers materials for use as permeability-reducing admixtures (PRAs) to be added to hydraulic-cement concrete mixtures exposed to hydrostatic conditions for the purpose of minimizing water ingress.
1.2 The function of this specification is to provide the means for evaluating the performance of a permeability-reducing admixture. This is accomplished by using a permeability-reducing admixture in making a watertight concrete test batch (see test Method Cxxx) from which test specimens are cast. Then, significant properties of the concrete are determined by tests and compared with the requirements of Section 3.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
There is currently no industry accepting standard specification for permeability-reducing admixtures [a.k.a. PRA or waterproofing admixtures] for hydrostatic conditions for concrete. In this specification the intent is to define the test procedures and acceptance criteria to be used for the purposes of qualifying a material as a permeability-reducing admixture for use in hydrostatic conditions. Concrete specifiers and other concrete professionals can use the standard performance requirements in this specification in project documents. A new standard test method for determining the depth of water penetration under pressure into concrete is also being balloted separately. This new standard test method is part of this new specification.
