Influence of the reuse of OSB and marine plywood formworks on concrete surface aesthetics

in Materials and Structures (2012), 45(9), 1331-1343

Concrete surface quality becomes more and more important because aesthetics requirements tend to spread over a wide variety of construction works. Even if it is difficult to clearly define what is ... [more ▼]

Concrete surface quality becomes more and more important because aesthetics requirements tend to spread over a wide variety of construction works. Even if it is difficult to clearly define what is beautiful or not, existing techniques maybe used to quantify aesthetic properties of concrete. As they mainly depend on formwork, the research project focuses on the reuse of two types of panels – plywood and OSB – and two types of release agents – vegetal and mineral oils. Evolution of surface properties is measured through lightness and absorption. For plywood formworks, beyond 80 reuses, a modification of surface quality is noticed; this is only 50 for OSB panels. For both types of formworks, the release oil doesn’t seem to have a major influence on formwork absorption. It is also observed that alkalis cause early degradation of the panels: release agents are not always efficient to avoid this phenomenon. Finally, if reuse doesn’t have any influence on the absorption of the plywood formworks, it is not the case for OSB formworks. [less ▲]

Recommendation of RILEM TC 200-HTC: mechanical concrete properties at high temperatures-modelling and aplpications. Part 2: Stress-strain relation

in Materials and Structures (2007), 40

This recommendation is valid for structural applications of concrete under service and accident conditions. This document presents test parameters (material and environmental) and tests procedures for ... [more ▼]

This recommendation is valid for structural applications of concrete under service and accident conditions. This document presents test parameters (material and environmental) and tests procedures for determining the stress-strain relation of concrete at constant temperature T,max after first heating or after cooling from T,max to ambient. [less ▲]

Adaptation of the pull-off test for the evaluation of the superficial cohesion of concrete substrates in repair works: analysis of the test parameters

in Materials and Structures (2004), 37(269), 342-350

Concrete repair works involve most of the time the removal of the damaged or contaminated surface layer. It is necessary to assess the effect of that operation (tool, procedure, etc) upon the integrity of ... [more ▼]

Concrete repair works involve most of the time the removal of the damaged or contaminated surface layer. It is necessary to assess the effect of that operation (tool, procedure, etc) upon the integrity of the residual concrete substrate, prior to the placement of the repair material, since it can affect significantly the adhesion of the repair system. This paper summarizes the findings of a study intended to develop a simple test method for that purpose. After a thorough review of the related scientific documentation, it has been decided to adapt the so-called pull-off test, which is commonly used to determine the bond strength of repair products. An experimental program has been conducted to evaluate the influence of various test parameters on the measured cohesion of a reference concrete surface: transfer plate thickness and diameter, core drilling depth, speed of loading, adhesive type and thickness, and number of tests. A multivaried statistical analysis of the test results clearly shows that the plate diameter and core depth are the most significant parameters, presumably with threshold values, and that there exists a synergetic effect between them. Also, a minimum number of tests can be defined based on the standard deviation and required level of confidence of the results. Overall, the test method shows good potential for a sound quantitative evaluation of a concrete surface mechanical integrity prior to repair, provided that the test parameters are selected properly. [less ▲]

Use of municipal solid waste incineration residues in the precasting of concrete paving

in Materials and Structures (2002), 35(250), 365-372

Valorisation of Municipal Solid Waste Incineration Residues - excluding ashes - is a positive advance in sustainable development: saving natural resources, decrease in wastes volume stored, reduction of ... [more ▼]

Valorisation of Municipal Solid Waste Incineration Residues - excluding ashes - is a positive advance in sustainable development: saving natural resources, decrease in wastes volume stored, reduction of energy consumption. If good conditions of incineration can be ensured and post-combustion treatments are realised, solid residues are in the form of granular materials usable in construction and civil engineering. Uses in road structures are classical; application for the precasting of paving is quite new and interesting due to the quantity of recycled materials. Mechanical and physical performances of municipal solid waste incineration residues let us to replace a part of the granular skeleton and to obtain similar behaviour as with reference granular composition: splitting resistance, water absorption and resistance to abrasion are optimised. Leaching behaviour is also verified in order to avoid detrimental effect on the environment; it is shown that post-combustion treatments and compacting energy combined with vibration are essential for a good quality product fabrication. [less ▲]

Environmental evaluation of materials and buildings processes : application of the life cycle analysis to the construction of an industrial hall

in Materials and Structures (2001), 34

Methodologies based on Life Cycle Assesment (L.C.A) give the opportunity to realise a global and complete evaluation of the environmental effects of products from their production to their use and ... [more ▼]

Methodologies based on Life Cycle Assesment (L.C.A) give the opportunity to realise a global and complete evaluation of the environmental effects of products from their production to their use and elimination (from craddle to grave); methods used for analysis are internationally wellknown and standardised. These methods are rarely used in construction materials area, although materials flows and energy consumption are important and constructions have a long way of life. A calculation methodology, based on ecofactors/ecopoints, has been used for the analysis of industrial hall made of concrete, steel, or concrete/wood structure; materials but also construction process are compared at the point of view of their environmental impact. This analysis completes the technical and economical approaches for the construction owner and designer and gives a global view of the interaction between construction and civil engineering, and environment. [less ▲]

Part 8: Steady-state creep and creep recovery for service and accident conditions

in Materials and Structures (2000), 33

Part 9: Shrinkage for service and accident conditions

in Materials and Structures (2000), 33

RILEM Recommendations : Part 6 – Thermal Strain

in Materials and Structures (1997)