Surface properties of concrete and criteria for adhesion of repair systems

in Van Gemert, Dionys; Kabashi, Naser; Nushi, Violeta (Eds.) et al Proceedings of the 1st Symposium on Polymers in Concrete (2013)

Before any repair operation, an effective assessment of the concrete substrate has to be performed. Usually next to the surface reparation of concrete, evaluation of the cohesion of the superficial ... [more ▼]

Before any repair operation, an effective assessment of the concrete substrate has to be performed. Usually next to the surface reparation of concrete, evaluation of the cohesion of the superficial concrete is requested for adhesion and durability reasons. Many authors describe the influence of the surface preparation technique on the superficial cohesion of concrete or the adhesion. However, the real effects of surface preparation technique only begin to be investigated in terms of superficial microcracking or roughness quantification. This project was performed in regards to the influence of concrete substrate strength and preparation technique efficiency. The effect of the concrete removal/preparation technique is most likely dependent upon the nature and the quality of the concrete substrate. Preparation techniques are compared from the point of view of concrete removing but also potential deterioration. The visual observation of the concrete surfaces indicates that the high pressure water jetting technique induces a particular texture characterized by large waves mostly parallel to the water flow. The concrete slabs have afterwards been covered with a Self-Compacting Repair Mortar and adhesion has been characterized. [less ▲]

Topography evaluation methods for concrete substrates: parametric study

in Alexander, Mark (Ed.) Concrete Repair, Rehabilitation and Retrofitting III (2012)

Research projects performed at the University of Liege, Laval University and the Warsaw University of Technology have pointed out the importance of taking care about the surface roughness of concrete ... [more ▼]

Research projects performed at the University of Liege, Laval University and the Warsaw University of Technology have pointed out the importance of taking care about the surface roughness of concrete substrate with regards to the adhesion of repair materials. This paper wants to make a State-of-Art on this specific problem: surfometry methods, interface analysis, adhesion measurements, …etc are presented, interpreted and compared. Surfology, which is a more wide concept, contributes to understand what will make the contact effective or not, and allow interactions of variable intensities between the materials. Different scales of observation – micro to macro - are needed to exactly represent what happens when materials are put into contact. [less ▲]

Concrete Repair Science: new trends - 10 Years cooperation between the University of Liège and the Politechnika Warsawska

Book published by Université de Liège (2010)

On the relation between bond quality and impact-echo frequency spectrum

in Proceedings of the 13th International Congress on Polymers in Concrete ICPIC 2010 (2010)

According to EN 1504-10 and ACI Concrete Repair Manual, bond strength and interface quality are the main features of repair system necessary to be assessed. Pull-off test is most commonly used for bond ... [more ▼]

According to EN 1504-10 and ACI Concrete Repair Manual, bond strength and interface quality are the main features of repair system necessary to be assessed. Pull-off test is most commonly used for bond strength evaluation but growing interest in nondestructive techniques (NDT) is recently noted. Impact-echo (IE) is treated as the most promising one for this purpose. The aim of this paper is to analyze an effect of bond quality on stress wave propagation in repair systems. A group of samples has been prepared in order to obtain repair systems of different bond quality. Prior to repair, quality of concrete substrates has been characterized according different techniques: compressive strength, superficial cohesion, surface roughness index and cracking quantification. Than a polymer-modified repair mortar has been applied. Af-ter hardening, IE signals have been recorded and pull-off bond strength determined. The rela-tionships between parameters characterizing surface quality, bond strength, IE frequency spec-trum and results of wavelet analysis of IE signal have been analyzed. [less ▲]

On the relation between bond quality and impact-echo frequency spectrum

in Restoration of Buildings and Monuments = Bauinstandsetzen und Baudenkmalpflege (2010), 16(4/5), 303-314

According to EN 1504-10 and ACI Concrete Repair Manual, bond strength and interface quality are the main features of repair system necessary to be assessed. Pull-off test is most commonly used for bond ... [more ▼]

According to EN 1504-10 and ACI Concrete Repair Manual, bond strength and interface quality are the main features of repair system necessary to be assessed. Pull-off test is most commonly used for bond strength evaluation but growing interest in nondestructive techniques (NDT) is recently noted. Impact-echo (IE) is treated as the most promising one for this purpose. The aim of this paper is to analyze an effect of bond quality on stress wave propagation in repair systems. A group of samples has been prepared in order to obtain repair systems of different bond quality. Prior to repair, quality of concrete substrates has been characterized according different techniques: compressive strength, superficial cohesion, surface roughness index and cracking quantification. Than a polymer-modified repair mortar has been applied. After hardening, IE signals have been recorded and pull-off bond strength determined. The relationships between parameters characterizing surface quality, bond strength, IE frequency spectrum and results of wavelet analysis of IE signal have been analyzed. [less ▲]

Surfology: what does it mean for polymer concrete composites?

in Restoration of Buildings and Monuments = Bauinstandsetzen und Baudenkmalpflege (2010), 16(4/5), 1-12

Surfology is a scientific concept including all surface properties of materials and its influence on adhesion. The study of adhesion of polymer concrete composites is on the border - interface - between ... [more ▼]

Surfology is a scientific concept including all surface properties of materials and its influence on adhesion. The study of adhesion of polymer concrete composites is on the border - interface - between materials science and engineering. Interface quality is clearly influenced by surface properties of materials. Quality is uneasy to define but, at the level of interface, it could integrate all what favours the contact between concrete and polymers, like shrinkage, rigidity, surface roughness, wettability, viscosity…etc. Surfology contributes to understand what will make the contact effective or not, and allow interactions of variable intensities between the materials. Different scales of observation – micro to macro - are needed to exactly represent what happens when materials are put into contact. The objective of the paper is to analyse the effect of surface parameters (surfology) on polymer concrete composites. Influence of water content, roughness and type of material will be taken into account as factor influencing wettability and thermodynamic properties of surface. Viscosity and shear level of resinous materials will be considered in the same way. Engineering point of view will be taken into account through adhesion evaluation and correlated to surface material properties. [less ▲]

The effect of concrete substrate quality towards evaluation of repair system using impact-echo method

in Szczesniak, W. E.; A. Zbiciak, A. (Eds.) Theoretical foundations of civil engineering (2009, September)

Surfology: concrete substrate evaluation prior to repair

in Mammoli, A.; Brebbia, C. A. (Eds.) Materials Characterization: computational methods and experiments IV (2009)

The study of adhesion of repair materials on concrete structures implies a good knowledge of the influence of concrete surface treatment. The effects of surface preparation technique are rarely clearly ... [more ▼]

The study of adhesion of repair materials on concrete structures implies a good knowledge of the influence of concrete surface treatment. The effects of surface preparation technique are rarely clearly described and parameterised: it is consequently difficult to point out the real influence of roughness on adhesion results. A large research project has been realized with regards to the influence of concrete substrate strength and preparation technique efficiency. The surface roughness of concrete has been quantified by means of the projection “Moiré” technique, which is an interferometrical measurement method. Comparison between polished, scrabbled and hydro-jetted surfaces evaluation is presented. [less ▲]

Evaluation of the effect of load eccentricity on pull-off strength

in Alexander, M. G.; Beushausen, H.-D.; Dehn, F. (Eds.) et al Concrete Repair, Rehabilitation and Retrofitting II (2009)

The efficiency of the composite repair system is usually evaluated through semi-destructive test: pull-off test. But some difficulties can also be induced by the eccentricity of the load application, due ... [more ▼]

The efficiency of the composite repair system is usually evaluated through semi-destructive test: pull-off test. But some difficulties can also be induced by the eccentricity of the load application, due to incorrect placement of the test device. The paper presents the results of a research project and the impact of incorrect design on tensile strength values. According to results of laboratory experiments and modelling, it can be observed that, if there is an influence of 2o and 4o angle of inclination on pull-off bond strength, it is however not statistically significant: the decrease of pull-off strength is usually no larger than 8% for 2o [less ▲]

Inżyneria powierzchni betonu. Część 2. Wpływ obrobki na powstawanie rys

in Materialy Budowlane (2006), 12