Polymers in Construction - September 2009

This month we're focusing on the topic of polymers used in buildings and other civil engineering applications.

Polymers are commonly used in a whole variety of ways in buildings and other areas of civil engineering. Many modern doors and windows have profiles made from PVC; building fascias and guttering are often plastic; insulation, wire and cable coatings are usually polymer-based; structural building reinforcement utilises polymers and hard surfaces like roads and playgrounds can have elastomers incorporated into them. Polymers are ideal for these long-term applications - the range available means you're sure to find a material that is durable even under tough conditions, yet also has the other properties required for that specific function.

Abstracts

Please see below a selection of abstracts highlighted in the September Newsletter. These are records which relate to polymers in construction applications that have been recently added to the Polymer Library.

Click on the 7-digit accession numbers to find out about ordering a copyright-cleared full text copy of the items shown.

1045491 - DIFFUSION MODELLING OF OIT DEPLETION FROM HDPE GEOMEMBRANE IN LANDFILL APPLICATIONS
The results of a diffusion modelling study conducted to evaluate experimental data on oxidative induction time(OIT) depletion from HDPE geomembrane(GM) in accelerated ageing tests are presented. Results are given of diffusion modelling of OIT depletion from a GM immersed in leachate and in a composite liner with leachate above the liner at different incubation temperatures. The results of the results of the diffusion model and the conventional first-order (exponential) antioxidant depletion model are compared. Estimates are made of diffusion and partitioning coefficients at typical landfill temperatures based on Arrhenius-type relationships, and the estimated parameters are used to model a composite liner with 30 cm thick sand layer. The antioxidant diffusion coefficients ranged from 2.1 x 10^-^1^5 (at 26 deg C) to 1.6 x 10^-^1^3 m^2/s (at 85°C) and the partitioning coefficients ranged from 720 (at 26°C) to 4 (at 85 deg C). The antioxidant depletion time obtained using the first-order model was similar to that predicted using the diffusion model for tests where the OIT was depleted during the test period. The first-order model, however, gave smaller predictions of depletion time than the diffusion model in cases where there was only limited OIT depletion and in these cases the diffusion model was likely to the give more accurate predictions. Arrhenius modelling provided a means of estimating diffusion and partitioning coefficients at field temperatures. At a typical landfill temperature of 35 deg C, the calculated antioxidant depletion time for the GM considered was about 130 years for a case where there was a 1.5 cm sand protection layer and 230 years for the case when 30 cm sand protection layer was used. These results thus suggested the use of a 30 cm sand protection layer in addition to the typical geotextile protection layer between the GM and a coarser granular leachate drainage layer would provide potential benefits in terms of extending the GM service life by reducing the rate of outward diffusion of antioxidants from the GM (as well as providing good physical protection of the liner). 46 refs.
Geosynthetics International, 16, No.3, 2009, p.183-196, ISSN: 1702-6349, DOI: 10.1680/gein.2009.16.3.183
Rimal S; Rowe R K

1045471 - HIGH HEAT RESISTANT COATING SYSTEMS
Coatings which retard the spread of fire or minimise fire-related damage to structures are discussed. The application areas, which are generally either industrial or institutional, are considered, including protecting people in fire escape routes in large buildings, protection of structural steelwork against collapse, e.g. in the interior of ships, and manufacturing plants in the chemical industry and other high fire risk businesses. The underlying mechanisms are described. Selection of flame retardants is considered, including halogen-containing compounds, antimony compounds, phosphorus-containing compounds, zinc borate, and metal hydroxides. Statistics are presented on the total heat resistant coatings market (powder and liquid) and on regional share % (NAFTA, Europe, China, South America).
Coatings World, 14, No.5, May 2009, p.30-31, ISSN: 1527-1129
Phillips P

1046234 - STRENGTHENING RC BEAMS IN FLEXURE USING NEW HYBRID FRP SHEET/DUCTILE ANCHOR SYSTEM
A new hybrid fibre-reinforced polymer(FRP) sheet/ductile anchor system for rehabilitation of reinforced concrete(RC) beams is described. The advantage of the proposed strengthening method is that it overcomes the problem of low ductility that is associated with brittle failure mode in conventional methods of strengthening beams using epoxy-bonded FRP sheets. The proposed system leads to a ductile failure mode by triggering yielding to occur in a steel anchor system (steel links) rather than by rupture or debonding of FRP sheets, which is sudden in nature. Four half-scale RC T-beams were tested under four-point bending. Three retrofitted beams were strengthened using one layer of CFRP sheet. The results for the two beams that were strengthened with the new hybrid FRP sheet/ductile anchor system were compared with the results from the beam strengthened with conventional FRP bonding method and the control beam. The results showed the effectiveness of the proposed strengthening system in increasing flexural capacity and ductility of RC beams. 26 refs.
Journal of Composites for Construction, 13, No.3, May-June 2009, p.217-225, ISSN: 1090-0268, DOI: 10.1061/(ASCE)CC.1943-5614.0000006
Galal K; Mofidi A

1046232 - CASE STUDY: SEISMIC UPGRADE OF A MASONRY BELL TOWER USING GLASS FIBER-REINFORCED POLYMER TIES
The case of the Bell Tower of Santa Maria del Carmine in Naples is discussed with reference to experimental studies conducted by the authors in-situ and to theoretical analysis using three-dimensional models. While the results obtained in the hypothesis of compact behaviour of the structure indicated a low risk condition under seismic actions, the study of local out-of-plane mechanisms provided evidence of an unsafe situation. To avoid such mechanisms, connective systems with tie rods made of glass fibre-reinforced polymer laminates were designed for insertion where local verifications were not satisfied. Design, application and monitoring procedures of this innovative intervention are discussed in detail. 13 refs.
Journal of Composites for Construction, 13, No.3, May-June 2009, p.188-197, ISSN: 1090-0268, DOI: 10.1061/(ASCE)CC.1943-5614.0000001
Ceroni F; Prota A

1046112 - THE DEVELOPMENT OF HDPE CORRUGATED DRAINAGE PIPE CONTAINING RECYCLED HDPE FOR HIGHWAY APPLICATIONS
The results are reported from the first two phases of a project aimed at determining if recycled PE could be incorporated into HDPE corrugated pipe for highway applications while maintaining specific short-term properties and long-term durability. The results of short and long-term tests on trial dual wall pipe samples are also reported. The effect of contaminants on the recycled materials is discussed and the properties of blends with natural post-consumer recycled HDPE and blends with mixed colour post-consumer reinforced HDPE are assessed. The project is sponsored by the Americal Association of State Transportation Officials through the National Cooperative Highway Research Program. 7 refs.
GPEC 2009: PLASTICS: THE WONDERFUL WORLD OF SUSTAINABILITY AND RECYCLING. Proceedings of a conference held Orlando, Fl., 25-27 Feb. 2009, Lindale, Ga., SPE, 2009, Paper 27, pp.51, CD-ROM, 012
Thomas R W

Special Offer

DON'T FORGET! The Building and Civil Engineering Applications bulletin is on offer until 20th November '09. It's a really quick and convenient way to keep yourself up-to-date on the latest developments in this area.

Visit the webpage to find out more or sign up.