Enhancement of adhesion properties between cement matrices and saturated substrates with asphalt mat by compatibilizing agents

Abstract

Maintenance of construction elements is a necessary intervention action; preventive and corrective, which directly interferes with durability, lifetime performance. The same goes for reservoirs, where the waterproofing system makes it watertight, guaranteeing the potability of the stored water, an essential situation for the ideal conditions of an enterprise. The old projects have, mainly, waterproofing with asphalt blanket in their reservoirs, when entering the maintenance schedule to revitalize the waterproofing system, the companies adopt the application of cementitious waterproofing agents, such as Polymeric Mortar and Acrylic Polymer Membrane with cement, where they have chemical incompatibility that prevents good adherence to the substrate saturated with asphalt emulsion and asphalt mat traces. This work aims to determine the best method for creating bonding bridges between the standardized substrate covered with asphalt mat and the cementitious composite added with four different types of compatibilization agents applied in cement: sand: additive: water as 1:1:0.5:0 and 1:1:0.25:0.25. The additives are Epoxy primer for wet bases; Styrene-Butadiene emulsion (SBR); Vinyl copolymer and Acrylic-based emulsion. After curing, to guarantee the perforation of all applied layers in an integral and standardized way, three holes with an exact internal diameter were perforated for all the plates, with and without the agents, to perform the adhesive tensile test by a dynamometer. The results show that the adhesive strength of the asphalt mat on the substrate equals 0.2 MPa, limit of the related standard, was met by all plates. All mixtures showed an increase in the adhesion of the cementitious material to the asphalt mat, when the additive concentration is increased. Only plates with Vinyl-0.50, SBR-0.50, Acrylic-0.25 and Acrylic-0.50 registered average strengths greater than 0.50 MPa, the minimum requirement of the related standard, and higher than the REF plate by 36%, 16%, 22% and 56%, respectively. The rest of the plates failed. Therefore, the influence on the performance in the adhesion of the composite to the asphalt mat is directly linked to the type of compatibilizing agent, as well as its concentration.