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which was selected from the contractor’s fleet of rotary machines given its compact size, maneuverability, and continuous electronic adjustment of rotor speed. The pumps were placed underground inside the pipes directly under the pipeline air vents, and filled continuously by the mobile batching plant above. The dry-mix material was delivered by compressed air through metal tubes to the nozzle operator at a maximum distance of 650 ft (200 m) from the pump. COLLABORATION WITH TECHNICAL UNIVERSITY OF CLUJ-NAPOCA The initial and early strengths were determined by means of penetrometer and stud driving testing on site, using an off-the-shelf penetrometer and a Hilti DX 450 SCT tool, respectively. The final compression strength was determined on 6 in. (150 mm) sample cubes cut from 3.3 ft (1 m) square panels. One test panel, which yielded three test cubes, was shot every 130 yd3 (100 m3) of sprayed concrete. The standards used for testing were: EN 12390-2, EN 14488-1:2011, EN 12390-3:2002, and EN 12390-4:2002. Each test was performed on the three cubes of a test panel, with average compression strength measured at 28 days between 5600 and 6100 psi (39 and 42 MPa), resulting in a concrete class of C30/37 (30 being the class of compression strength and 37 the specific compression strength on standard 6 in. 150 mm sample cubes). The testing was performed on a state-of-the-art Avantest 9 servo-hydraulic machine. For future works, the Faculty of Civil Engineering’s Laboratory suggested performing energy absorption tests on slabs according to EN 14488-5:2006. SIGNIFICANCE OF SHOTCRETE WORK Shotcrete was proven to be the most effective method for the rehabilitation of the Suhurlui Irrigation Pipeline, given the constraints imposed by the project Owner: 2016 OUTSTANDING UNDERGROUND PROJECT Project Name Rehabilitation of the Suhurlui Irrigation Pipeline Project Location Galati, Romania Shotcrete Contractor Matei Construct Constructii Speciale SRL General Contractor Matei Construct Constructii Speciale SRL Architect/Engineer Artifex Engineering SRL, Romania Material Supplier/Manufacturer Ocmer Co. SRL, Italy Project Owner: F.O.U.A.I. Campia Covurlui • Extension of the service life of the pipeline for a minimum • Minimum disruption to the crops and agricultural land: digging was necessary only to create access holes; and • Minimum cost: no expensive, large-diameter replacement steel pipes were required. Using the existing degraded metal pipe wall as formwork, a new reinforced concrete pipe was created inside the existing pipe, with a minimum reduction of nominal diameter. ABOUT THE CONTRACTOR Matei Construct Constructii Speciale Ltd. (MCCS) is a leading Romanian company headquartered in Cluj-Napoca, the city-capital of Romania’s Transylvania region, that delivers specialized civil, industrial, and infrastructural works. Shotcrete is a process used by the company’s three business units: Environment Engineering (Water Plants and Waste Water Treatment Plants), Infrastructure (tunnel lining, anchoring and slope stabilization), and Industry (large water and sewer pipes, canals, and refractory). Calin Mircea, PhD, is the Chair of the reinforced concrete course at the Technical University’s Faculty of Civil Engineering in Cluj-Napoca, and Owner of Artifex Engineering Ltd. Ofelia Corbu, PhD, is the Head of the Central Laboratory of the Faculty of Civil Engineering in Cluj-Napoca. Eugen Maier, BSc, specializes in technologies for environment engineering and currently serves as Technical Director of MCCS. Cristian Rus, PhD, is the Commercial Director of MCCS. of 15 years; www.shotcrete.org Winter 2017 | Shotcrete 45


2017WinterShotcreteEMag
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