The technical design of ETEM factory (Sofia) requires the specialized conveyor stretching machine to be monolithic fitted by using of system of steel anchor rods with a diameter of 30 and 40 mm and different lengths (600-700 mm), which have to be grouted in pre-left holes with a diameter of about 150 mm in steel-reinforced concrete foundation slab.
The technically determined anchoring depth determines the total thickness of the anchor layer within 700-800 mm, reaching the “lower edge of the steel support plate”. The company’s produced grouting compositions generally have significant limitations in terms of the maximum allowable thickness of a single layer – usually up to 30-40 mm, which implies multi-stroke implementation to fill the entire anchoring depth.
Given the above, and mainly, taking into account the conditions of laying and the specifics of the operating mode of the facility, thepossibility to use concrete batching plant produced high-strength self-compacting fiber-reinforced concrete with compensated shrinkage (to some degree of self-stressing) is estimated as an attractive alternative from a technical and financial point of view.
After the innovative mix design of that an innovative composition of concrete and its casting in real production conditions, specialized laboratory tests were conducted to prove its strength-deformation characteristics – compressive strength, tensile strength in bending, modulus of elastic deformation and shrinkage characteristics. The obtained results prove that the required high technical and technological characteristics of the concrete mix and the hardened concrete are completely achieved precise for the specific application ca se.
- Valeriy B. Naidenov, Mirona K. Mironova, Opportunities for drying shrinkage minimizing in fiber-reinforced concrete overlays for repairing of corroded industrial structures, Materials, Methods & Technologies ISSN 1314-7269, Volume 14, 2020 (32-40).
- Cao Q, Y. Cheng, M. Cao, Q. Gao, “Workability, strength and shrinkage of fiber reinforced expansive self-consolidating concrete”, Construction and Building Materials, vol. 131, 2017.