Concrete is made by mixing cement, water, coarse and fine aggregate, and various admixtures. The basic aim of mixing these ingredients in measured amounts is to make concrete that is easy to transport, place, compact, and finish and that will set and harden to create a strong and durable product.
With growing demand for concrete, new challenges have been posed to concrete technologists/researchers. Recently, strong emphasis has been laid on "quality concrete" that has the following characteristics:
- High early strength
- High performance
- Shorter construction time
- Changing the properties of the basic ingredients of concrete
- Developing new ingredients called admixtures
Today, concrete technologists face numerous difficulties that need to be addressed. On one hand, designing high-performance and high-strength concrete requires newly developed admixture, and on the other hand, it has been observed that, due to the same admixture, the concrete undergoes excessive shrinkage and cracking. Thus, the very purpose of using such mixtures is defeated. Another burning issue facing concrete technologists is related to curing concrete. What should be the timing, duration, and type of curing? What should be the balance between the curing time and the speed of the construction? These are some of the questions that need further research in order to be answered.
Another problem facing the concrete industry is that of producing "Green Concrete." In the field of science and engineering, the concern over global warming and ecological changes is growing. The concrete industry's contribution to these environmental changes has been significant. Just consider the fact that in order to produce one ton of Portland cement, it requires up to 7000 MJ of energy, and it produces around one ton of carbon dioxide. These adverse impacts on the environment have forced the concrete industry to identify environmentally friendly practices and processes.
Still another challenge faced by the concrete industry is the "knowledge gap." Research and development carried out at research institutes need to be disseminated to the practitioners for implementation. An effective training program would be very effective in bridging the knowledge gap. Some of the topics that could be useful in such a training program are:
- The properties of individual concrete ingredients
- Interactions of various ingredients in concrete mixtures
- Arriving at the optimum mixture for different types of applications
- Desired level of exposure to adverse environments
In brief, it can be summarized that the concrete industry needs researchers/concrete technologists who can carry out well-planned basic research. These research programs should focus on promoting and developing comprehensive understanding of the properties of concrete and its ingredients. Also, new and improved methods of testing concrete and its ingredients should be evolved. And finally, the knowledge and methods acquired in lab research should be transferred to concrete practitioners for implementation.