Investigating the compatibility between repair materials and damaged substrate concrete

Dissertant

Sadun, Tahsin Diwan

Thesis advisor

Furayyih, Qays Jawad
Hasan, Man Salman

University

University of Technology

Faculty

-

Department

Department of Building and Construction Engineering

University Country

Iraq

Degree

Master

Degree Date

2012

English Abstract

A wide variety of repair materials are available for use with repairs on concrete.

These materials possess a broad range of physical and mechanical properties.

Previous investigations on the durability of repairs indicate that among the principal reasons for premature failures of concrete repairs is the improper selection of repair materials, based on repair materials properties without investigating the compatibility between the repair material and the substrate concrete.

Composite section of repair materials and substrate concrete are considered to be compatible only in case of withstanding all stresses induced by applied load under different environments over a designed period of time.

In this study, the compatibility of five different types of repair material (conventional mortar, polymer-modified mortar, silica fume mortar, and two commercial mortars (EUCOGROUT and HSXtra mortar)) with two types of substrate concrete (C25 and C50) is investigated in three stages.

First, individual properties such as flow, compressive strength, flexural strength, bond strength, drying shrinkage, porosity, and chloride ingress of the repair materials are measured.

Second, the compatibility is evaluated, using a flexure test on a composite beam under third point loading.

Third, the correlations between the individual properties of repair materials and the performance of the composite beam under flexural loading are explored to predict the durability of the repaired concrete.

Total number of (337) specimens are cast, cured, and evaluated, using standard test procedures.

Results show that these mechanical and physical properties of repair material are significantly varied from each other.

Low water cement ratio causes decrease to drying shrinkage and reduces the risk of cracking.

Through the regression analysis on the experimental data collected, power relation with coefficient of determination (R2) of 0.766 is obtained between compressive and flexural strength.

Compatibility stage results indicate that the shape of the edge of the area being repaired has a significant effect on flexural strength and the failure mode observed in the composite prisms.

It is also observed that no significant correlation of individual repair materials exists with the compatibility.

However, bond strength and drying shrinkage have the highest correlation coefficient (Average R2=0.8193 and 0.8168 respectively), while porosity and chloride ingress have lowest correlation coefficient (Average R2=0.3797 and 0.2470 respectively) with the composite beam.

Main Subjects

Civil Engineering

Topics

• Standards

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-419254