Penetration depth for water repellent agents on concrete as a function of humidity, porosity and time
2006 (English)In: Restoration of Buildings and Monuments, ISSN 1864-7022, Vol. 12, no 1, 3-16 p.Article in journal (Refereed) Published
Water repellent agents are used on concrete to change the conditions for moisture transport and fixation and thereby protect the concrete and the reinforcement bars from, e.g., chlorides, frost damage and alkali silica reactions. The most frequently discussed topic regarding water repellent treatments is the penetration depth of the agent. What is required and what is needed to achieve it? The effective penetration depth of a water repellent agent is defined as the distance from the surface to the sharp line between dry and wet concrete after it has been sprayed with water. During the past decade several papers have been published where factors having a major influence on the penetration depth for different water repellent agents have been investigated. The conclusions that can be drawn from these papers are that the three most important factors are time, porosity and degree of saturation. The time referred to is the duration of contact between the water repellent agent and the concrete surface. The porosity and degree of saturation refer to the concrete pore system and the amount of moisture inside the concrete at the time of the impregnation. There is, however, a lack of investigations quantifying the influence of these factors. This paper presents an empirical equation that gives an idea on how much these factors affect the efficient penetration depth of the water repellent agent. The equation is based on 300 new tests described and analysed in the paper. It is clear that the polymerisation rate of the water repellent agent affects the penetration depth. A fast reaction has the effect of slowing down the penetration.
Place, publisher, year, edition, pages
2006. Vol. 12, no 1, 3-16 p.
water repellent agents, peneration depth, concrete
IdentifiersURN: urn:nbn:se:kth:diva-6303OAI: oai:DiVA.org:kth-6303DiVA: diva2:10981