Drilling Resistance Measurement System (DRMS)
Analytical technique description:
Micro-destructive technique that allows to assess the superficial "hardness / cohesion" of natural or artificial stone material both in laboratory and in situ. The instrument is constituted by a modified drill in which a load cell allows to measure, in newtons, drilling resistance of the material under examination. The instrument creates a hole on the surface under examination with a bit of 5mm of diameter and the hole depth is established by the operator (usually 10mm). The forward and rotational speed of the bit are kept constant during the test and selected according to the type of material to be analyzed. The instrument connected to a PC with specific software allows you to view real-time diagram of drilling resistance as a function of the depth of the hole.
Applications:
Assessment the state of conservation of natural and artificial stone materials (mortar / cement, earthen materials, brick, etc.). Evaluation of the efficacy of conservative treatments of natural and artificial stone materials and monitoring over time: detection of the depth of penetration of the treatments and possible formation of surface crusts (thickness and hardness).
Quality assessment of quarry material for replacement in situ.
Basics:
The drilling resistance of a natural or artificial stone material is a function of its compositional, mechanical and microstructural characteristics and was statistically correlated with the uniaxial compressive strength.
Instrumental details:
Cordless Drilling Resistance Measurement System (DRM) SINT Technology (Florence Unit).
ICVBC - AREA DI RICERCA CNR DI FIRENZE
Via Madonna del Piano, 10 - 50019 Sesto Fiorentino (FI)
Tel. 055 5225484 - Fax 055 5225483
Institute for the Conservation and Valorization of Cultural Heritage