Shrinkage restrained

S. P. Shah, M.E. Karaguler and M. Sarigaphuti Effects of Shrinkage-Reducing Admixtures on Restrained Shrinkage Cracking of Concrete. ACI Materials Journal, No.89-M33, May-June, (1992), p. 289-295. 

FIGURE 3.15 Finite difference mesh in the case two-dimensional drying with shrinkage (a) before deformation (b) after deformation. Broken line—for unrestrained shrinkage, solid line—for restrained shrinkage. 

The restrained shrinkage cracking behavior was measured by the total crack width of each ring specimen with respect to time. The crack widths were significantly reduced in the fiber composites, including all recycled fibers except those with rubber strips. In the recycled carpet fiber composites, the crack width and spacing were evenly distributed. The crack widths were much larger than those with steel fibers, and about one half of those with FiberMesh. 

Malmberg, B., Skarendahl, A. (1978) Method of studying the cracking of fibre concrete under restrained shrinkage, in Proc. RILEM Symp. Testing and Test Methods of Fibre Cement Composites, R. N. Swamy ed., The Construction Press pp. 173-9. 

N. Banthia, M. Azzabi, and M. Piegon, Restrained Shrinkage Cracking in Fiber Reinforced Cementitious Composites , Mater. Struct. 26,1993, 405-413. 

K. Kovler, J. Sikulerand A. Bentur, Restrained Shrinkage Tests of Fibre Reinforced Concrete Ring Specimens Effect of Core Thermal Expansion , Mater. Struct 2(>, 1993, 231-237. 

It is interesting to note the differences in the data obtained from free and restrained shrinkage tests. For example, from the results reported by Malmberg and Skarendahl [10] it can be seen that the addition of 1 % by volume of steel fibres led to a reduction of only about 10% in the free shrinkage, while the total crack width in a ring test was reduced by about 80%. Thus, the information provided by the two types of tests with respect to the effect of fibres can be quite different. 

H. Krenchel and S.P Shah, Restrained shrinkage tests with pp-fiber reinforced concrete , in S.P. Shah and G.B. Batson (eds) Fiber Reinforced Concrete Properties... 

N. Banthia, C. Yan and S. Mindess, Restrained shrinkage cracking in fibre reinforced concrete A novel test technique , Cem. Concr. Res. 26,1996, 9 14. 

R.N. Swamy and H. Stavrides, Influence of fibre reinforcement on restrained shrinkage and cracking , J. Amer. Cone. inst. 73,1979, 443-460. 

K. Kovler, J. Sikuler and A. Bentur, Restrained shrinkage tests of fibre reinforced concrete ring specimens effect of core thermal expansion . Mater. Struct (RiLEM). 26, 1992, 231-37. 

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