Core Cutting & Testing

The 4” diameter diamond bit, increasing horsepower from 1.5 HP to 7 H produced significantly increase in penetration rate with only gradual decrease in drilling ratio. The decrease in drilling ratio was much slower than what occurred for 2” diameter bit because the larger surface area of the 4” diameter diamond bit distributed the thrust over a wider area. The penetration rate in non-reinforced

Concrete continued to increase even at highest horsepower used in test 7 HP. However in reinforced concrete drilling ratio dropped rapidly as horsepower was increased. Similarly penetration rate reached a plateau at about 4 HP. Using power above this level in reinforced concrete produced only minor increases in Penetration Rate.