Comportamiento de Sistemas Provisionales de Protección de Borde de polietileno de alta densidad frente a cargas estáticas y de impacto

Abstract

We have tested under static and dynamic load temporary edge protection systems (TEPS) formed by a continuous fence, some are made of high density polyethylene (HDPE) and others have been manufactured using a composite material, adding glass fiber at a matrix of HDPE at a rate of 4%.Tests under static and impact have been performed according to standard UNE-EN 13374, class systems A and B. It has been found the influence of aging on TEPS and samples of the same materials as the TEPS.All tested TEPS exceed the strength requirements and accidental load and requirements compared to dynamic loads. The incorporation of glass fibers results in a composite material with a modulus of elasticity higher and significantly less creep. We haven't seen dependence on the results with the degree of aging or in SPPB or in the samples.Keywords: polymer; fiberre in forced; composite; flexural strength; creep. RESUMENSe han ensayado bajo cargas estáticas y dinámicas sistemas provisionales de protección de borde (SPPB) formados por una valla continua, unos fabricados con polietileno de alta densidad (HDPE) y otros con un material compuesto, añadiendo un 4% de fibra de vidrio a una matriz de HDPE.Los ensayos, bajo cargas estáticas y de impacto, se han realizado según la norma UNE-EN 13374, para sistemas clase A y B. Se ha comprobado la influencia del envejecimiento sobre SPPB y probetas de los mismos materiales que los SPPB.Todos los SPPB ensayados superan los requisitos de resistencia y de carga accidental y los requisitos frente a cargas dinámicas. La incorporación de fibras de vidrio da lugar a un material compuesto con un módulo de elasticidad significativamente más alto y con menor fluencia. No se aprecia dependencia de los resultados con el grado de envejecimiento ni en los SPPB ni en las probetas. INTRODUCTIONPolyethylene is a thermoplastic polymer combining a series of physical and mechanical properties such as a low density and a good strength-weight ratio, which together with the easiness to process it, becomes suitable for a great variety of applications, being plastic the mostly produced one (1, 2). Depending on the polymerization process employed, different types of polyurethane are obtained depending on the density. High density Polyurethane (HDPE) usually has densities in between 0.94 and 0.97 g/ cm 3 , the longitudinal elasticity is low, around 2000 N/mm 2 and presents high fluency values even for loads far from its elastic limit and for a short time, mainly for stress concentrators producing a fragile failure process (3-5).HDPE has excellent properties to be used as a component in collective protections (CP), where stresses are produced, mainly as impacts. The low value of the elasticity module, together with the great deformations reached before fracture, implies the possibility of absorbing a great quantity of energy. However, the low elasticity modules can be an inconvenience in certain occasions, as movements higher than the admitted by the standards regulating CP used are reached with HDPE systems. Moreover, agi...

Requirements for the Preliminary Design of Innovative Temporary Edge Protection Systems (TEPS) for Construction Works

“…Based on these results, plastic materials are discarded due to their low performance in bending tests. On the contrary, previous studies analysed the high-density polyethylene (HDPE) materials to be applied but in surface (non-linear) elements [62]. Likewise, both the reference material and cast iron and carbon-fibre-reinforced polymer are postulated as good candidates for the next stage of the study.…”

“…Systems: There is a wide variety of collective protection systems available on the market for the construction sector, such as systems embedded in the concrete in plastic cartridges inserted into slabs, jaw-type posts tightened in concrete structures or fixed to metal profiles, clamp-type posts that can be fixed onto a wide range of slab edges, integrated safety systems used in the execution of formwork, telescopic vertical struts, V-type safety nets, etc. Likewise, within these systems, there are railings, nets, plinths and wire mesh which cover the gaps through which falls can occur, as well as anchoring systems, including flanges and uprights, with specific designs for their coupling; • Materials: The most commonly used material for the manufacture of railings and uprights is galvanised steel [59], although other types of material such as aluminium [60], wood [61] or high-density polyethylene (HDPE) [62] can also be found, among others.…”

Static load behavior and energy absorption of safety guardrails for construction works

“…The influence of aging has been studied on TEPS made with HDPE and subjected to natural ageing. (González, Cobo, Lozano & Bresó, 2013). The continuous fence is formed by three horizontal elements, 150 mm in height, two vertical elements at the edges, and diagonal elements 200 mm wide with intermediate spaces located at the top and bottom rectangular spaces.…”

Innovative temporary edge protection system in trench works for the construction industry and rescue operations

“…Moreover, a number of studies have shown that a TEPS is an excellent collective protection system that prevents a substantial number of falls from height accidents [17][18][19][20]. However, several static load and impact studies evaluating the performance of several TEPS [21][22][23][24][25][26] have found certain conventional TEPS failed to meet the international standards and specifications on the geometric and dynamic requirements of TEPS [27][28][29][30][31]. It should be noted that these standards and specifications vary considerably worldwide [32].…”