free surface

In this paper, a new finite-difference-solution technique for solving transient seepage problems with an unknown free sur ace has been proposed. The governing finite-difference equations were derived using flux conservation in the general case of anisotropic and nonuniform permeabilities and variable grid spacing, and these equations were modified by the extended pressure (EP) method Transient seepage problems may be easily solved by the proposed solution technique, which is based on an iterative spreadsheet calculation. The technique was illustrated by several free-surface seepage problems analyzed previously by several researchers, and good agreement was obtained.C1 Pamukkale Univ, Fac Engn, Dept Civil Engn, Denizli, Turkey.Anadolu Univ, Fac Engn & Architecture, Dept Civil Engn, Eskisehir, Turkey

An experimental study on the evaluation of concrete test results

The compressive strength test applied to standard samples is one of the most important tests indicating the quality of concrete in structures. The results of the standard tests are compared with the values used in design calculations to check for specification compliance and quality assurance. Although the standard tests are well accepted by the construction industry, they may not represent the in-situ strength of concrete due to the differences between the degree of compaction and curing conditions of concrete and those of standard samples. The quality of concrete can be assessed by means of minor-destructive methods. Pull-out test is an example of minor-destructive tests. The test causes only minimal destruction to the structure and the hole is repaired easily after testing. In the present study, the results from pull-out tests, and maturity method were extensively analysed for the assessment of concrete strength. © RILEM 2013