Paper Details
F. Papworth. 2009. Perth. WA.
Chemical resistance tests, Design life, Allowable damage, Risk assesment, Exposure assesment, Sulphate resistance, Cation effect, Penetrability, Testing for sulphate resistance, Standards, Influence of SMC's, High magnesium sulphate solutions, Salt etching, Acid resistance.
This paper discusses the short comings in exisiting Australian standards in relation to durability design, and the consequent effect on clear financial modelling of alternate durability specifications and various design lives. The concept of applying risk assesment methods to appraise elements of durability specifications is introduced. A suggestion to standardise durability modelling based on the structural design approach is included. Some key elements of a durability plan are discussed.
F. Papworth and Vile. G. 2008. Pit to Port Symposium. The Australian Geomchanics Society. NSW.
The paper specifically considers in-ground deterioration applicable to loaders, linings, railways, slabs and ports. Deterioration mechanisms considered include cracking, corrosion, and chemical attack (including acid sulphate soil issues). The rate of decay is dependent on the access and penetration of contaminants and their subsequent reaction with the concrete and steel. The paper reviews these processes to give a logical approach to design. The importance of cement systems to provide chemical resistance, mix design to provide impermeable paste, and aggregate selection to avoid integral problems are discussed.
F. Papworth. 2008. Perth. WA.
Durability analysis is often a difficult part of the design in structures subject to severe exposures. The brief for design and construct projects often quote national standards as a minimum requirement and require a specified design life be achieved. This paper shows how national standards are often out of date and this places the responsibility on the Contractor to ensure that state of the art durability designs will provide the serviceability required over the design life. The paper shows how the detailed assessment of exposure, the thorough analysis of deterioration mechanisms and the specification of materials and construction methods can be used to calculate an appropriate design life. It also gives insight to the Durability Consultants endeavours to present competitive designs whilst obtaining performance beyond that which national standards would provide. The paper shows how risk assessment and probability are increasingly used as means of determining performance and maintenance requirements.
F. Papworth. 2008. The Institute of Engineers. Malaysia.
Durability Plans are a requirement on many infrastructure projects. This paper reviews the durability planning process including consideration of design life and risk assessment. Testing requirements at all stages of a project are reviewed.Requirements for aggregates, methods of water control, strength specification, cover checking, Non Destructive Testing (NDT) and condition monitoring are considered. Exposure of concrete in air, the ground and marine environments are discussed including exposure levels for sulphates, chlorides and leaching. Key aspects of placing, including plastic cracking, plastic settlement, compaction and curing are discussed. Some critical design aspects are considered, including early age thermal cracking.
F. Papworth. 2008. Perth. WA.
F. Papworth. 2007. CIA. Perth. WA.
This paper reviews some of the recurring issues that arise in regards to the durability of concrete
on mining projects. Initially design life, Australian Standards and risk assessment are discussed
to give a background to designing for durability.
Items discussed include crack control and quality assessment of insitu cast concrete and
shotcrete, common deterioration mechanisms and concrete subject to extreme chemical
exposure.
The paper shows that concrete is immensely versatile due to a variety of admixtures, cement
systems and design solutions available. However, these solutions are seldom considered in mining projects.
F. Papworth and Marosszeky. M. 2007. Australia.
Durability analysis is often a difficult part of the design in structures subject to severe
exposures. The brief for design and construct projects often quote national standards as a
minimum requirement and require a specified design life be achieved. This paper shows how
national standards are often out of date and this places the responsibility on the Contractor to
ensure that state of the art durability designs will provide the serviceability required over the
design life. The paper shows how the detailed assessment of exposure, the thorough analysis
of deterioration mechanisms and the specification of materials and construction methods was
undertaken on major desalination plants, pipe lines, tunnels, bridges, coal unloader and water
storage plants. The paper gives insight to the durability experts endeavours to present
competitive designs whilst obtaining performance beyond that which national standards would
provide. The paper includes assessment of the use of supplementary materials, coatings,
inhibitors and cathodic protection. It provides methods of assessing ground water attack,
chloride ingress, cracking and corrosion rate. It also shows how risk assessment and
probability are increasingly used as means of determining performance and maintenance
requirements.
August 2007 Grand Medina Hotel