The aim of the endoscope survey is to classify in detail the consistency and nature of the material making up the structure under examination, by means of visual and photographic surveys. For this purpose, a rigid or flexible probe is used, which is inserted into some holes in the masonry by means of a core drill or electric drill.
The photographic or video feedback from the inspection allows any anomalies inside the masonry to be detected.
Surveys using flat jack
Survey with a single flat jack aims to determine the state of compressive stress existing in a portion of masonry. For this purpose, a flat jack of semicircular shape was used, inserted in a notch made on the masonry with a special cutter.
The result enables comparison with the maximum resistance of the masonry resulting from a test with a double jack or through laboratory tests on portions of masonry.
Surveys using double flat jacks
The purpose of the double flat jack investigation is to determine the value of the existing tension on the masonry, the elastic modulus and the tensile strength of a portion of masonry between two semicircular jacks. The survey is carried out after the normal test on a flat jack, in order to associate the stress on the portion of masonry with its maximum tensile strength.
Sonic / ultrasonic measurements
Ultrasound is used to measure the mechanical properties of masonry, in particular its elasticity and homogeneity. To carry out the test, the emitting probe and the receiving probe can be placed on opposite surfaces of the element to be investigated (direct measurement), on the same surface (indirect measurement) or on perpendicular surfaces (semi-direct measurement). The emitting probe produces pulses that are picked up by the receiving probe and recorded by the equipment. The transit time gives an indication of the elastic modulus of the masonry at different points.
The purpose of taking masonry samples is to obtain a sample, consisting of the element brick and bedding mortar, on which to perform laboratory tests to characterise the physical, chemical and mechanical materials, assess the degradation, compressive strength and identify the type of material to use to restore the masonry.
The elements taken, representative of the masonry texture, are flattened on the contact surfaces in order to ensure the correct distribution of the load.
Tests using single and double flat jacks on masonry, endoscopic surveys and samples of mortar intended for laboratory tests.