Building & Construction

Research & Consultancy

Concrete Inspection
Durability Planning
Concrete Materials
Concrete Repair
Concrete Structures
Concrete Crack Control
Concrete Fire Test
Geopolymers
Shotcrete
Silica Fume
Timber

Paper Details

1. “Durability Related Testing and Monitoring For Concrete Construction Specifications”

F.Papworth, R.Barnes and K.Mathieu. April 2006 Concrete Institute of Australia, Melbourne

Non Destructive Testing (NDT) and monitoring are being increasingly specified for checking key performance related parameters and for assurance of long term durability.  This paper considers selected parameters used in durability design, discusses their significance and outlines how testing or monitoring can be used to reduce the associated risk of premature deterioration. Specific parameters discussed are:

  • post pour cover measurement to check the adequacy of the construction method 
  • monitoring the corrosion activation front ingress rate to verify design assumptions
  • use of bleed measurements to plan pours to avoid plastic shrinkage and settlement cracking
  • field and laboratory sorptivity measurement to verify penetrability performance
  • impact echo thickness measurement of liners (slabs and tunnels)
  • rebound hammer strength testing to verify early age strengths

 

2. “Field Techniques for Non Destructive Testing (NDT) of Existing Concrete Structures”

R.Barnes & F.Papworth. 2005 Concrete Institute of Australia 22nd Biennial Conference, Concrete, Melbourne, Australia.

Techniques developed over the last 20years such as Reinforcement Electrical Potentials, Impact Echo and Ground Penetrating Radar are becoming main stream investigation methods while methods such as Linear Polarisation Resistance, Concrete Resistivity, Torrent permeability and initial surface absorption tests (ISAT) are little used. This paper will describe the accuracy, simplicity, cost and applicability of each method to explain why this is so.

Digital rebound hammer, Ultrasonic Pulse Velocity, Reinforcement Cover Meters, Reinforcement Electrical Potentials, and Ground Penetrating Radar have improved markedly with the development of digitalisation. New instruments will be described to show how these well known methods have improved due to digitisation.

Additionally the limitations of various methods used for different applications will be explored including:

  • Ground Penetrating Radar, Impact Echo, Reinforcement Cover Meters and Reinforcement Electrical Potentials when measuring prestressing duct and rebar location and integrity
  • Internal defect identification using Impact Echo and Ultrasonic Pulse Velocity
  • Strength measurement using Ultrasonic Pulse Velocity and Digital rebound hammer with and without correlation tests to the mix

Concrete quality assessment using Ultrasonic Pulse Velocity, Torrent permeability and Sorptivity Tests. The overview presented will be useful to those not expert in testing to determine what method to employ in different circumstances. Whilst including some theory the paper will also explore some of the practicalities of employing different methods of NDT.

 

3. “Establishing Time To Corrosion And Corrosion Rate Of Reinforcement To Give Life Assessments”

R.Barnes & F.Papworth. 2007 Australasian Corrosion Association Annual Conference

This paper aims to give an overview of Non-Destructive Test’s used in life assessment of concrete structures and how they have developed in recent years. Covermeters, Linear Polarisation Resistance, Corrosion monitoring, Resistivity and Half Potentials are all examined. The T0 + T1 life assessment technique is then summarised with the view to explain how these Non-Destructive Test’s can be helpful in monitoring how a marine structure is behaving relative to the predicted life. Each Non-Destructive Test is analysed with respect to its effectiveness in giving quantitative information regarding the life assessment of a structure.

 

4. “Investigation of Concrete Structures”

F.Papworth. Winter 2004, Australasian Corrosion Association and Concrete Repair Association road show to Sydney, Melbourne, Adelaide, Perth, Brisbane & Hobart

Includes detailed visual assessment guide and advice on planning a survey. Latest developments in practical field non-destructive testing equipment used for the routine assessment of reinforced concrete structures are discussed. This includes the current status of European and US codes and standards. Methods of using the new Digi-Schmidt (rebound hammer) are outlined including the accuracy of compressive strength assessments. The combination of ultrasonic and rebound number to give a more accurate assessment of strength is explained. Testing of tensile strength of concrete and bond of shotcrete, coatings and overlays using pull off testers is discussed. The accuracy of measuring reinforcement’s cover and diameters is described. Fast scanning and isolated measurement of reinforcement potentials and concrete resistivity to assess corrosion initiation and rate is outlined. Means for in the field identification of chloride and carbonation penetration are presented. Techniques for measuring permeability and sorptivity of concrete in-situ without damaging the concrete are given.

 

5. "Sydney Harbour Tunnel - Technical Aspects of Asset Maintenance Strategies for Long Term Serviceability“

Marosszeky, M., Chang, Z. T., Munn, R. L., Cox, I., Cherry, B. and Walters, P., 2002 9th International Conference on Durability of Building Materials & Components, Brisbane, Australia, March,.

 

6. "Potential Curvature Method - A new Approach for Corrosion Assessment in Concrete Structures",

Chang, Z. T., Cherry, B. and Marosszeky, M., 2002 9th International Conference on Durability of Building Materials & Components, Brisbane, Australia,