Many infrastructure deterioration problems and failures can be traced back to the cracking and brittle nature of concrete. It enhancing the ductility of concrete materials. Most fibre reinforced concrete results in enhanced post peak tension-softening behaviour under tensile load. This improved toughness is useful in resisting the propagation of cracks into major fractures by energy absorption in the bridging action of fibers in the fracture process. While the fracture toughness of concrete can increase by an order of magnitude by fibre reinforcement, the tensile strain capacity usually remains little changed. In recent years, efforts to convert this quasi brittle behaviour of fibre reinforced concrete (FRC) to ductile strain- hardening behaviour resembling ductile metal have met with varying degrees of success. In most instances, the approach is to increase the fibre content as much as possible and processing techniques are adapted to overcome the resulting workability problem. Cement based composite such as slurry infiltrated fibre concrete (SIFCON) and slurry infiltrated mat concrete (SIMCON) are good examples of this approach, which utilizes from 5 to 20% volume content of steel fibers.


SIFCON

Slurry infiltrated fibre concrete is a combination of cement, aggregate, fibre and water with some admixture. SIFCON is developed construction materials using steel fibers with cement matrix. The matrix consists of cement mortar slurry. The fibre bed is infiltrated with cement based slurry by gravity flow. Hence, the optimization of the flow of matrix of cement slurry is, as important step in the as design of its composition. Slurry infiltrated fibre concrete is (SIFCON) can be considered as a special type of fibre concrete with high fibre content. The matrix usually consists of cement slurry or flowing mortar. SIFCON has excellent potential for application in areas where high ductility and resistance to impact are needed. Only very limited information is available about its behaviour under different types loading. Tests on 22- mm thick SIFCON specimen were carried out to study their behaviour in flexure and under subjection to abrasion and impact loads. Toughness characteristics of SIFCON were also evaluated by testing another set of specimens 100x100x500 mm per ASTM C1018. Both strength and deformation characteristics of the specimens were studied. The results obtained from these tests were compared with those carried out on companion plain mortar and conventional fibre - reinforced mortar (FRM) specimens.

The investigation confirm the superior characteristics of SIFCON as compared with plain mortar and normal FRM. SIFCON, which have number of outstanding properties such as strength, ductility, toughness, durability, stiffness and energy absorption capacity under monotonic and cyclic loads. The properties of SIFCON are achieved through an optimized combination of matrix properties, fibre reinforcing parameters, fibre content and interface characteristics between fibre and matrix. It is observed that the presence of SIFCON in over reinforced concrete beams leads to ductility indexes exceeding three times those obtained without it. Cracks width and spacing are more than an order of magnitude smaller than in conventional reinforced concrete. Experimental results also suggests that there is no need for stirrup in flexural members with a SIFCON matrix.


SIMCON

The cost of civil infrastructure constitutes a major portion of the national wealth. Its rapid deterioration has thus created an urgent need for thr development of novel, long lasting and cost effective methods for repair, retrofit and new construction. A promising new way of resolving this problems is to selectively use advanced composites (HPFRCCs). With such materials, noval repair, retrofit and new construction approaches can be developed that would lead to substantially higher strengths, Seismic resistance, ductility, durability, while also being faster and more cost - effective to construct than conventional methods. SIMCON which stands for Slurry Infiltrated Mat Concrete is well suited for the development of novel repair, retrofit and new construction solutions that lead to economical and improved structural performance. 

SIMCON (slurry infiltrated mat concrete) is a non-woven steel fiber mat that is infiltrated with concrete slurry. it is shown that the SIMCON concept of reinforcement represents a significant improvement in the reinforcement efficiency in high density, high strength fibre reinforced concrete. Comparable levels of flexural strength and flexural energy absorption capacity can be achieved at greatly reduced fiber loading relative to the short, discrete fiber reinforcement approach. SIMCON, uses a manufactured continous mat of interlocking discontinuous steel fibers, placed in a form, and then infiltrated with a flow able cement based slurry. The use of continous mats, typically made with stainless steel to control corrosion in very thin members, permits development of high flexural strengths and very high ductility with a reduced volume of fibers.