Concrete future trends

This chapter discusses current research on the use of sulfur in recycled asphaltic concrete pavements. In addition, it describes the results of laboratory tests and theoretical predictions using the latest linear viscoelastic layered pavement analysis methods (15,16) to compare the performance of various sulfur-asphalt concrete pavements with conventional asphalt concrete pavements in a variety of climates. The relationship between pavement distress and performance used in the computer program was established at the AASHTO road test (17). Finally, the results of domestic field tests of sulfur-asphalt pavements are presented along with a discussion of future trends for the utilization of sulfur in the construction of highway pavement materials. 

D.W.Fowler (1989). Future Trends in Polymer Concrete. ACISP116 8,pp 129- 143. 

Keywords Concrete-polymer composites. Polymer-modified concrete. Polymer concrete. Polymer-impregnated concrete. Principles of process technology. Research and development. Standardization work. Sustainable concrete-polymer composites. History, The recent and future trends. 

Abstract. The present paper deals with the principles of process technology for concrete-polymer composites, the research and development history of the concrete-polymer composites, the recent trends in the research and development of the concrete-polymer composites and the present status of major standardization work for the concrete-polymer composites, on the basis of comprehensive literature survey. The future trends in the research and development of the concrete-polymer composites are predicted, and sustainable concrete-polymer composites are proposed for the 21st century. 

This section will present some well-established apphcations of fibre-reinforced mortars and concretes, as well as the developments in recent years and future trends. 

As a recent trend, there have been a few attempts to use polymer latexes with chemical admixtures such as superplasticizers,alkyl alkoxy silane,and amino alcohol derivativeP I at low polymer-cement ratios of 5.0% or less. A trial to inhibit alkali-aggregate reaction with chemical admixtures and SBR latex has also been done.l When such attempts are completed, new polymeric chemical admixtures for ordinary cement concrete may successfully be developed in the near future. 

The future growth of concrete-polymer composites may depend considerably on the relative cost of polymers for them [87], An important raw material for the polymers is petroleum. With an increase in the cost of the petroleum in the present world economic trends, the likelihood of the polymers becoming more expensive seems a foregone conclusion [87]. This will provide many difficulties for the future development or growth of the concrete-polymer composites. 

As Y. Ohama says the early deterioration of reinforced concrete stmctures has been a big social problem in the world in recent years and he continues the future growth of sustainable concrete-polymer composites such as polymer modified mortar and concrete, and polymer mortar as repair materials is globally expected . P. Seidler states innovations cannot be forecasted innovations need firstly leisure time and thus money . It will be important for the development of the field polymers in concrete that the future technical trends will be well defined and that a good balance between time and money could be achieved. 

I would like to be concrete on this particular point. With mounting concern I have observed how here in Sweden, as in many other countries, while basic schooling for the majority of our citizens has improved there has been an Increase In various types of what can only be described as occult trends. A lack of faith In the future together with a strong mistrust not only in the political establishment but also In the Intellectual establishment to which the world of research belongs, - these are far from uncommon today. To put It... 

Polymers, after their combination with fibres to form special composites produces some materials with enhanced properties, enabling them to be used as structural members and units, competing with metals. The use of polymeric fibres in concrete to replace steel frame (as composite rebars) has many advantages which has been in use for a long time with an ever increasing trend in use, if the material costs involved are decreased in the future, as expected. However, proper materials characterisation in addition to development of new standard test methods still appear to be the immediate needs to be fulfilled in the near future. 

This large market includes residential housing and commercial building, in addition to roads, bridges, and other elements of the infrastructure. The largest volume of adhesives presently used is for nonstructural applications however, the use of structural adhesives is expected to increase in the future. While some end uses will involve primary structural bonds, most will be semi-structural, in which the adhesive will be used in combination with a mechanical fastener. The use of adhesives is also expected to increase as the trend towards the manufacture of prefabricated sections continues. Laminated beams and trusses are one established use for structural adhesives, typically phenolic, but there is now interest in urethanes for this purpose. Epoxies are also widely used, mostly for the bonding and repair of concrete. 

In the mix composition of advanced cement-based materials a few admixtures for improving their special properties in fresh and in hardened states are normally included (cf. Section 4.3). In particular, different water reducers and plasticizers are used in a large majority of concrete production. This trend will intensify in the future, based on the results of investigations. 

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