Journal ZhBI i Konstruktsii, ¹2, 2013: Ten Reasons for ROCKMESH
june 26, 2013
Composite wall ties are rods of a circular cross-section with thickenings on the ends, which act as anchors in masonry joints. Wall ties are used for connection of bearing and facing layers in production of reinforced concrete three layer sandwich panels for large panel construction.
Introduction of composite wall ties for reinforced concrete and brick structures brought solutions to many problems of construction industry. Thus, for example, replacement of steel connectors and wall ties for composite ones improved quality and strength of objects under construction, eliminated thermal bridging. Along with increase of thermal efficiency of buildings up to 30% application of composite wall ties reduces construction costs. According to data of MAPID JSC, one of the leading construction organizations of Belarus, due to use of basalt fiber reinforced polymer (BFRP) wall ties instead of steel ones thermal resistance of external walls increases by 14%.
One of the key advantages of BFRP wall ties is their low thermal conductivity (BFRP has 0.46 W/m2, steel – 56 W/m2). Therefore thermal conductivity of BFRP is 100 times less than steel. BFRP wall ties solve the problem of “thermal bridging” caused by steel constructions. Bright spots on thermographic images indicate location of steel reinforcing bars, which cause heat losses. With BFRP wall ties it is possible to cut costs for heating up to 20-30%.
Another important feature of the ties is their high corrosion and chemical resistance. BFRP material does not corrode; it is resistant to aggressive alkali environment of concrete. Its low density allows increasing load on a building footing. Wall ties made of BFRP are 3.7 times lighter than those of steel. Due to high strength and durability of BFRP proved by tests conducted by NIIZhB (Moscow) and the University of Sheffield (Great Britain), the material retains its properties even in alkali and thermomoist conditions. Feasibility of BFRP materials use is obvious: construction with them is 3-5 times cheaper than with traditional materials. BFRP wall ties comply with all fire safety requirements: tests performed according to GOST 30247.0-94 30247.1-97 revealed that fire-resistance rating of a concrete panel with BFRP wall ties is not less than 151 minutes.
Since the beginning of the 2000-s GALEN BFRP wall ties have been used in projects of Novocheboksarsk building factory (Chuvashia), then deliveries to other regions of Russia and CIS countries (Kazakhstan, Belarus) started. The next stage of product development was its recognition abroad. Upon the results of successfully passed tests in Great Britain, GALEN BFRP wall ties were awarded BBA Certificate (British Board of Agreement) and have come into use in construction of British passive houses.
Composite mesh ROCKMESH
Competitive price for innovative solution ROCKMESH combined with its unique physical and chemical properties makes it preferable to steel mesh. Moreover, with composite mesh used for reinforcement of a sandwich panel external layer it is possible to reduce concrete consumption by 20%.
Why ROCKMESHAdvantages of composite mesh
High strength. Composite rebars used in ROCKMESH resist higher loads in tension, bending and pull-out than steel ones of the same diameter: they are 3-4 times stronger. Therefore steel mesh can be replaced by composite with rebars smaller in diameter (for example, 2mm diameter composite mesh can be used instead of 3mm diameter steel mesh).
High corrosion and chemical resistance. ROCKMESH has excellent resistance to chemicals, salts and corrosion in high moisture and aggressive conditions.
Light weight. Weight of the most commonly used steel mesh (50x50x3mm, 0.5x2m) is 2.22 kg/m2, while composite mesh of analogous dimensions weighs 0.36 kg/m2, i.e. it is 6 times lighter.
Low conductivity. Unlike steel meshes and wall ties embedded into wall, their composite analogues do not cause thermal bridging and do not reduce thermal efficiency of structures.
Reliability and durability. According to the results of tests held in the University of Sheffield (Great Britain) environmental reduction factor for a period of 100 years in wet conditions is 1.25 which corresponds to strength retention of 79.6% (accelerated tests in aggressive environment).
Low modulus of elasticity allows damping vibration quickly and without any consequences.
When breaking of a concrete structure, ROCKMESH holds its shape preventing further failure of the object.
“Products manufactured by GALEN have been used in Russia and abroad for more than 15 years. Billions of cubic meters of natural gas have been saved due to increase of thermal efficiency and millions of square meters of housing have been built over this time,” – says Valery Nikolaev, General Director of GALEN, in his speech at the conference in Rostov-on-Don. Industrial production and mass application of composite mesh will save concrete consumption, reduce construction costs and deliver solutions to a number of technological problems. Formulation and introduction of documents regulating the use of composite materials and reinforcing bars will mean a new stage in development of construction industry and large panel construction, in particular. Use of BFRP wall ties allows saving of concrete consumption by 20%.
Reference:Composite mesh ROCKMESH is designed for:
- reinforcement of concrete slabs, beams, exposed to high moisture and aggressive environment: floor coverings, bathrooms, objects of chemical production, agricultural and coastal structures;
- reinforcement of brick and stone walls of buildings and structures;
- reinforcement of an external layer of a concrete panel in large panel construction; concrete elements exposed to chemicals and salts: industrial floor coverings, coastal structures, cooling towers, bridges, dams, etc.;
- reinforcement of road concrete surfaces, treated with anti-icing agents and salts;
- guarding of highways and railways.