Global PVC resin production stands at 30 million tonnes and PVC stabiliser consumption at 560,000 tonnes. The global market for PVC heat stabilisers amounted to 1.5bn US dollars in 2005. Asia-Pacific accounts for over 40% of global consumption by volume, Europe 32% and North America 16%. Resin manufacturing and the nature of stabilisers have undergone a tremendous change during the past decade as a result of regulatory limitations of hazardous substances, as well as efforts to make the material recyclable and compliant with sustainability requirements. Lead stabilisers still account for 50% by volume, with use high in Asia-Pacific and Europe, but very low in North America. Technological options to replace heavy metal stabilisers, such as calcium/zinc systems, are discussed.

Chemical foaming agents are used to produce foamed plastics in sheet or profile extrusion, injection moulding and rotomoulding for a wide variety of applications. Use of foaming agents is driven by several, primarily cost-saving, factors. Reducing part weight by 5% will immediately pay for the cost of the foaming agent. However, a more typical weight saving of 20-40% results in a much greater overall cost saving. CFAs also improve throughput or cycle time by acting as a lubricant. The most widely used type of CFA, with about 88% of global CFA volume, is azodicarbonamide, an exothermic CFA that produces nitrogen on decomposition. Processors in Europe are under pressure to replace ADCA with endothermic CFAs in food applications in order to be in compliance with the EC's Directive 2004/1/EC, which suspends use of ADCA in food contact materials. Applications for CFAs, including automotive, electronics, packaging and building, are outlined.

Packaging is providing opportunities for North American compounders as their customers seek ways to grab the attention of consumers. In the automotive industry, North American auto and light-truck builds were down almost 2% through mid-November and could drop further still in 2007. At LNP Engineering Plastics, however, auto-related sales actually are up 1% so far in 2006, a result of focusing on under-hood and inside-cabin parts, rather than large parts like bumpers. In M&A, the compounding deal that got the most attention in 2006 was one that did not happen. Ferro's plan to sell its specialty plastics business to Wind Point Partners fell through. While North American compounders may be uncertain about the future, many are adding extrusion lines and growing their businesses.

Fibre-reinforced polymer (FRP) tubes filled with concrete are very effective structural elements when loaded under axial stress. The exterior jacket of FRP, in fact, confines the inner concrete and significantly enhances both its resistance and stiffness. On the other hand FRP protects the inner core from temperature and humidity effects, and may also be used both as formwork and as reinforcement. Nonetheless, stability problems arise when FRP tubes are used as slender structural elements. Although the physical behaviour of a straight structural element is simple, state-of-the-art models on one side do not deal explicitly with instability effects, on the other do not offer closed form solutions for the longitudinal constitutive relationship. Both aspects are solved and validated in this work. First a closed form constitutive relationship for concrete filled FRP tubes is developed. Departing from this solution, the critical load is computed in closed form. Secondly, the constitutive models for squat and slender tubes are validated against experimental results and compared with other state-of-the-art models. Design charts for FRP tubes under compression including buckling are obtained as a function of the most important variables and used to verify example elements. The proposed model shows a good capability of describing the behaviour of FRP-concrete tubes, while being simple to use, expressed in a closed form and hence computationally fast. 25 refs. Copyright (c) 2006 Elsevier Ltd.

In order to prevent tension delamination of concrete cover in mid-span more efficiently, an attempt to strengthen reinforced concrete beams by combining unidirectional carbon fibre reinforced polymer (CFRP) sheet (to bond to the tension faces of the beams) and bi-directional glass fibre reinforced polymer (GFRP) sheet (to wrap 3 sides of the beams continuously) was proposed. The feasibility and potential advantages of the attempt were discussed. A comparative test program including ten beams was carried out. The test results showed that the hybrid CF/GF reinforced polymer (H-CF/GF-RP) strengthening could not only prevent the tension delamination of the bottom concrete cover, but also lead to a significant increase of deformation capacity of the strengthened beams at a very low cost compared to CFRP strengthening. 8 refs. Copyright (c) 2006 Elsevier Ltd.

Water based polymer systems are often used for improvement in the properties of plain cement mortar or concrete. Presently, latexes of a single or combinations of polymers like polyvinyl acetate, copolymers of vinyl acetate-ethylene, styrene-butadiene, styrene-acrylic, and acrylic and styrene butadiene rubber emulsions are generally used. One of the limitations of these polymer systems is that they may re-emulsify in humid alkaline conditions. To overcome this problem, an epoxy emulsion based polymer system has been developed. In this paper the properties of the cement mortar modified with this newly developed epoxy emulsion are compared with those of the acrylic-modified mortar. The results showed that the mortars with the newly developed system have superior strength properties and better resistance to the penetration of chloride ions and carbon dioxide. 10 refs. Copyright (c) 2006 Elsevier Ltd.

Glass fibre-reinforced polymer (GFRP) tubes are compared to steel spiral reinforcement in circular concrete members with longitudinal reinforcement and prestressing, using six beam tests. Two 324mm diameter and 4.2m long prestressed specimens were tested in bending. Four 219mm diameter reinforced specimens were also tested, including two 2.43m long beams tested in bending and two 0.6m long beams tested in shear. In each set, one specimen was essentially a concrete-filled GFRP tube, while the other control specimen included steel spiral reinforcement of comparable hoop stiffness to that of GFRP tube. The strength of control specimens was governed by crushing and spalling of concrete cover. Unlike spiral reinforcement, GFRP tubes confined larger concrete areas and also contributed as longitudinal reinforcement, leading to increases in flexural and shear strengths, up to 113% and 69%, respectively. 12 refs. Copyright (c) 2006 Elsevier Ltd.

The purpose of this study is to evaluate mechanical properties of control and modified asphalt mixtures. Conventional and five modified asphalt mixtures were studied on hot mix asphalt permanent deformation resistance. Amorphous polyalphaolefin, cellulose fibre, polyolefin, bituminous cellulose fibre and styrene butadiene styrene were used as modifiers. Indirect tensile strength, indirect tensile, static and repeated creep and LCPC wheel tracking tests were used for different loading conditions and temperatures. Research was focused on comparing the interaction between LCPC wheel tracking and other mechanical tests. According to the LCPC wheel tracking and repeated creep test results SBS mixtures were found as the most resistance mixtures in view of the rutting. Additives performed different performance levels but showed more resistance to permanent deformation according to the conventional mixtures. As far as the static creep test results are concerned there are controversial results because conventional mixtures are better. It is thought that this result may stem from the static behaviour of the load and rheological change of bitumen with modifiers. 29 refs. Copyright (c) 2006 Elsevier Ltd.

Strengthening and rehabilitation of structures is a major concern for researchers in the civil engineering community in recent years due to the ageing of these structures and the need for effective methods of strengthening. This paper presents the results of an experimental study of the behaviour of strengthened steel-concrete composite girders using Carbon Fibre Reinforced Polymers (CFRP) plates. Strengthening was achieved by attaching the CFRP plates to the bottom flange and in some beams the CFRP plates were also attached to the beam web. Two different types of CFRP plates were used being mainly different in the tensile modulus of elasticity. Shear stress distribution along the bond line between CFRP plates and steel was recorded and reported. The test results showed that using lightweight CFRP plates could enhance the strength and stiffness of steel-concrete composite girders up to 45% of the original strength. 13 refs. Copyright (c) 2006 Elsevier Ltd.

Grouting is a common technical method with many applications, e.g. it is used for soil stabilisation and strengthening, for reduction of water ingress to underground facilities or of the water loss through a dam foundation, etc. Grouts comprise several constituents, which are combined in many ways depending on the in situ conditions and the outcome desired. Superplasticisers, accelerators, antifreezers, air-entraining agents and many others are generally used to improve the quality of cement grouts and consequently, their effectiveness on strength (especially bond strength), durability, impermeability and resistance to chemical erosion of the grouted soil or rock mass. A comprehensive laboratory work was carried out in order to study the physical and mechanical properties of grouts prepared by using cement, clay, water in different percentages along with an amount of acrylic resin or methyl methacrylate co-polymer emulsion. Flowability, setting time, bleeding, compressive strength, elastic modulus, shear bond strength, resistance to wet-dry cycles and resistance to sulphate attack of the grouts were determined. The results of this study indicated that the addition of latexes improves significantly the compressive strength, shear bond strength, stability, resistance to wet-dry cycles and resistance to sulphate attack, especially for thick pure cement grouts. This improvement depends on the type of latex. 12 refs. Copyright (c) 2006 Elsevier Ltd.

This paper presents an experimental study on the fire behaviour of glass fibre-reinforced polymer (GFRP) load-carrying slabs for building and bridge applications. Fire experiments were performed on cellular full-scale slabs with and without internal liquid cooling. The slabs were subjected to serviceability limit state loads during ISO 834 fire exposure from the underside. Liquid cooling was demonstrated to be an effective way of improving the fire endurance. The code-required 90-minute fire resistance for buildings was met. After an increase in the first 20min, temperatures, deflections, and axial strains of the liquid-cooled slabs approached a nearly steady-state condition in the 70-100min that followed. The remaining total safety factor in post-fire experiments was greater than 3.3 and therefore still sufficient to prevent structural collapse. The non-liquid cooled reference specimen provided structural resistance during fire exposure for 57min. For bridge applications, it was concluded that the fire endurance of non-liquid cooled cellular GFRP bridge decks is sufficiently high in the case of fire from the underside. 9 refs.

This paper examines the effect of fibre orientation angle of composite material (T300/5208) on the phenomenon of humidity diffusion. Using an analytical method, humidity concentration through the thickness of plates of E-glass/epoxy and carbon/epoxy (T300/5208) composites are calculated. This method also predicts the saturation in humidity and the time to saturation. Analytical formulations have been proposed [G. Verchery, Moisture diffusion in polymer matrix composites with cyclic environmental conditions, Developments in the Sciences and Technology of Composite Materials, in: A.R. Bunsell, J.F. Jamet, A. Massiah (Eds.), Proceeding of the 5th European Conference on Composites Materials (ECCM5), European Association For Composite Materials (EACM), Bordeaux, France (1992) 505; E. Adda-Bedia, W.S. Han, G. Verchery, Moisture diffusion in polymer matrix composites with cyclic environmental conditions, Textile composites in building construction (TCIBC 1992), in: P. Hamelin, G. Verchery (Eds.), Proceeding of the International Symposium Textile Composites in Building Construction, Pluralis, Paris, Part. 2, Lyon, France (1992a) 127; W.S. Han, E. Adda-Bedia, G. Verchery, Diffusion de l'humidite dans une plaque composite soumise a des conditions d'environnement cycliques'', Anales des Composites, Publication editee par l'AMAC (1992) 29; E. Adda-Bedia, W.S. Han, G. Verchery, Simplified methods for prediction of moisture diffusion in polymer matrix composites with cyclic environmental conditions, International Journal of Polymers and Polymer Composites 6 (4) (1998) 189] to solve Fick's equation which describes the kinematics of hygroscopic absorption in materials. The diffusivity in composites being a very important parameter, the present model is described in detail. In addition, a study of the effects of environmental conditions and fibre orientation angle on saturation values and ageing degradation of E-glass/epoxy composites exposed to hygrothermal conditions is proposed. 23 refs. Ltd.

An overview of building materials from local resources is briefly presented with a particular attention on natural fibres based composites. Natural fibres are low-cost, locally available in abundance and obtained from renewable resources. At the Central Building Research Institute, Roorkee, the potential of sisal and jute fibres as reinforcements have been systematically investigated to overcome their well-defined problems of moisture absorption. The performance of polymer composites made from these natural fibres and unsaturated polyester/epoxy resin was evaluated under various humidity, hygrothermal and weathering conditions. Consequent to this, various composite products such as laminates/panels, doors, roofing sheets, shuttering and dough moulding compound have been prepared. The suitability to these products is assessed as an alternate material according to the existing Indian standard specifications. The process know-how for the manufacturing of natural fibre composite panels/door shutters has also been commercialised. 27 refs.

Fibre reinforced polymers (FRPs) constitute a class of advanced composite materials which have the potential to change significantly masonry rehabilitation and strengthening. Their light weight means that they do not alter the mass of a structure and thus the inertial forces from seismic excitation. Their strength and, in the case of sprayed glass FRP, their toughness, indicate that they can alter the load deformation response considerably for the better. Further testing is required, but FRP's open an exciting new line of possibilities for masonry. 81 refs.

Multilayered aluminium-coated polymer laminates are the common barrier envelopes of vacuum insulation panels used as thermal insulations in building applications. These laminates are made of up to ten distinct layers including three barrier layers made by vacuum web coating. The thickness of each aluminium layer (30-100 nm) influences the overall thermal performance of the panels as well as the temperature at joints between adjacent panels. Two commercially available barrier envelopes have been investigated by means of focused ion beam etching for an adequate determination of the effective thickness of the aluminium layers. Additional information has been gained on interfacial failure between aluminium and its neighbouring polymeric film or adhesive layer as well as disruptions in the aluminium layer itself. These provide hints related to air and moisture permeation, the key properties of barrier envelopes in building applications where a lifetime of 20 to 50 years is required. 20 refs.