schmidt Hammer - Introduction.

SCHMIDT CONCRETE REBOUND TEST HAMMER

BRIEF INTRODUCTION

 

Concrete is susceptible to a variety of environmental degrading factors which tend to limit its service life. This therefore has brought about the need for test methods to measure the in-place properties of concrete for quality assurance and for evaluation of existing conditions. Since such test are expected not to impair the function of the structure and allow for re-testing at the same location to evaluate the changes in property at some other point in time, these methods should be non-destructive. Hence the Concrete Test Hammer.

Concrete structures as many other engineering structures, are subjected to deterioration that affects their integrity, stability and safety. Faced with the importance of the damages noted on the structures, the current choices are directed towards the repair of the existing structures rather than towards the demolition and construction of new ones. But before any repair work being done, it is common practice to determine the causes of the deterioration so that successful repair can be done.

 

Many repair work such as Road Highways fail because the exact causes of the deterioration was not adequately identified. This identification process comprises many methods including non-destructive testing methods. Non-Destructive Testing (NDT) is usually undertaken as part of the detailed investigation to complement the other methods. The conclusions of the investigation are based essentially on these tests. A correct assessment of a deteriorated concrete structure is a crucial basis for the success of a repair system.

 

Experience has shown that in many cases repairs fail much earlier than expected due to improper diagnosis of the actual situation of the structure, either because the cause of the degradation was not properly understood, or the extent of the damage was under-stated. The strength of the concrete structure will vary by age but its rate may depend on various factors such as the type of concrete, type of aggregate, surface and internal moisture condition of the concrete etc. Since, the use of Schmidt hammer is commonly accepted for the preliminary assessment of concrete surface hardness as the non-destructive test, this will provide useful estimation of the uniformity of concrete and measure the strength of existing surface concrete and to detect weak spots.

 

 

 

 

 

TEST BETTER – BUILD STRONGER