Delamination of Bonded Concrete Overlays at Early Ages


Book Description

A procedure is developed by which the likelihood of delamination of bonded concrete overlays on continuously reinforced concrete pavements is reduced. The procedure compares the early age interface stress to the expected interface bond strength for a variety of environmental conditions. When the calculated stress exceeds the expected strength, it is recommended that overlay placement be curtailed until the possibility of debonding is reduced. A finite element method program is used to determine the early age stresses resulting from temperature and shrinkage induced volume changes. Stresses were determined for a variety of environmental and material combinations and overlay thicknesses. Analyses show that a significant reduction in stress results from the use of overlay materials which have a lower modulus and thermal coefficient than those of the existing slab. The stresses for a given combination of materials and environmental conditions are compared to the interface bond strength at early ages. Early age interface shear and tensile strengths are estimated from 7-day strength test results. The estimated strength, together with the variability of the interface strength, are used to calculate the likelihood of delamination for a given type of overlay and time of placement. This likelihood can be reduced through the selection of a different overlay material or time of placement.




8th RILEM International Conference on Mechanisms of Cracking and Debonding in Pavements


Book Description

This book presents the latest advances in research to analyze mechanical damage and its detection in multilayer systems. The contents are linked to the Rilem TC241 - MCD scientific activities and the proceedings of the 8th RILEM International Conference on Mechanisms of Cracking and Debonding in Pavements (MCD2016). MCD2016 was hosted by Ifsttar and took place in Nantes, France, on June 7-9, 2016. In their lifetime, pavements undergo degradation due to different mechanisms of which cracking is among the most important ones. The damage and the fracture behavior of all its material layers as well as interfaces must be understood. In that field, the research activities aims to develop a deeper fundamental understanding of the mechanisms responsible for cracking and debonding in asphalt concrete and composite (e.g. asphalt overlays placed on PCC or thin cement concrete overlay placed on asphalt layer) pavement systems.




Failure, Distress and Repair of Concrete Structures


Book Description

Understanding and recognising failure mechanisms in concrete is a fundamental pre-requisite to determining the type of repair, or whether a repair is feasible. This title provides a review of concrete deterioration and damage, as well as looking at the problem of defects in concrete. It also discusses condition assessment and repair techniques.Part one discusses failure mechanisms in concrete and covers topics such as causes and mechanisms of deterioration in reinforced concrete, types of damage in concrete structures, types and causes of cracking and condition assessment of concrete structures. Part two reviews the repair of concrete structures with coverage of themes such as standards and guidelines for repairing concrete structures, methods of crack repair, repair materials, bonded concrete overlays, repairing and retrofitting concrete structures with fiber-reinforced polymers, patching deteriorated concrete structures and durability of repaired concrete.With its distinguished editor and international team of contributors, Failure and repair of concrete structures is a standard reference for civil engineers, architects and anyone working in the construction sector, as well as those concerned with ensuring the safety of concrete structures. - Provides a review of concrete deterioration and damage - Discusses condition assessment and repair techniques, standards and guidelines







An Introduction to Overlays for Continuously Reinforced Concrete Pavement for Professional Engineers


Book Description

Introductory technical guidance for civil engineers, highway engineers and other professional engineers and construction managers interested in overlays for continuously reinforced portland cement concrete pavements. Here is what is discussed: 1. INTRODUCTION, 2. TYPES OF OVERLAYS INVOLVING CRC PAVEMENT, 3. GENERAL APPROACHES TO OVERLAY DESIGN, 4. CRC OVERLAY TYPES AND PERFORMANCE.




An Introduction to Resurfacing of Continuously Reinforced Concrete Pavement


Book Description

Introductory technical guidance for civil engineers and construction managers interested in resurfacing continuously reinforced portland cement concrete pavement for streets and highways.




Bonded Cement-Based Material Overlays for the Repair, the Lining or the Strengthening of Slabs or Pavements


Book Description

Among different approaches that can be considered for concrete rehabilitation, bonded overlays are often the most economical alternative. The primary purpose of overlays is to extend the life of the candidate structures, either by restoring the quality and integrity of the surface and/or the re-establishing or improving the load-carrying capacity. Nevertheless, the durability of bonded overlay systems still draws concerns in the technical community because of bond sustainability problems encountered in a number of cases. At this time, there is still no accepted design approach or methodology that can warrant the practitioner a successful outcome of the repair. This State-of-Art report summarizes the findings with respect to all aspects involved in the overlaying process.




Handbook on Nondestructive Testing of Concrete


Book Description

Civil engineers will value this resource that examines the tools and techniques used to estimate the in-place strength on concrete, permeation properties that relate to potential durability, and the methods used to assess the internal condition of concrete and the corrosion activity of steel reinforcement.




Principles of Chemical Engineering Processes


Book Description

Written in a clear, concise style, Principles of Chemical Engineering Processes provides an introduction to the basic principles and calculation techniques that are fundamental to the field. The text focuses on problems in material and energy balances in relation to chemical reactors and introduces software that employs numerical methods to solve these problems. Upon mastery of this material, readers will be able to: Understand basic processing terminology (batch, semibatch, continuous, purge, and recycle) and standard operations (reaction, distillation, absorption, extraction, and filtration) Draw and fully label a flowchart for a given process description Choose a convenient basis for calculation for both single- and multiple-unit processes Identify possible subsystems for which material and energy balances might be written Perform a degree of freedom analysis for the overall system and each possible subsystem, formulating the appropriate material and energy balance equations Apply the first law of thermodynamics, calculate energy and enthalpy changes, and construct energy balances on closed and open systems Written as a text to fully meet the needs of advanced undergraduate students, it is also suitable as a reference for chemical engineers with its wide coverage across the biochemical and electromechanical fields. Each chapter of the text provides examples, case studies, and end-of-chapter problems, and the accompanying CD-ROM contains software designed for solving problems in chemical engineering.




Rheology of Fresh Cement and Concrete


Book Description

This book brings together new research information on the flow behaviour of cementitious materials from the UK, France, Italy, Germany, Poland, Finland, USSR, USA and Japan, presented at the International Conference organised by the British Society of Rheology in March 1990.