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High performance fiber-reinforced concrete (HPFRC) has been frequently investigated in recent years. Plenty of studies have focused on different materials and types of fibers in combination with the concrete matrix. Experimental tests show that fiber dosage improves the energy absorption capacity of concrete and enhances the robustness of concrete elements. Fiber reinforced concrete has also been illustrated to be a material for developing infrastructure sustainability in RC elements like façade plates, columns, beams, or walls. Due to increasing costs of the produced fiber reinforced
concrete and to ensure the serviceability limit state of construction elements, there is a demand to analyze the necessary fiber dosage in the concrete composition. It is expected that the surface and length of used fiber in combination with their dosage influence the structure of fresh and hardened concrete. This work presents an investigation of the mechanical parameters of HPFRC with different polymer fiber dosage. Tests were carried out on a mixture with polypropylene and
polyvinyl alcohol fiber with dosages of 15, 25, and 35 kg/m3 as well as with control concrete without fiber. Differences were observed in the compressive strength and in the modulus of elasticity as well
as in the flexural and splitting tensile strength. The flexural tensile strength test was conducted on two different element shapes: square panel and beam samples. These mechanical properties could
lead to recommendations for designers of façade elements made of HPFRC.
The level of energy consumption in renovation activities of buildings has huge advantages
over the demolition of old buildings and the construction of new structures. Such renovation activities
are usually associated with the simultaneous strengthening of their elements, such as externally
bonded carbon fibre reinforced polymer (CFRP) lamellas or sheets on vertical and horizontal surfaces
as structural reinforcements. This means the process of refurbishing a building, as well as the
raw materials themselves have a significant impact on CO2 emissions and energy consumption.
This research paper demonstrates possibilities of replacing state of the art, highly energy-intensive
CFRP lamellas with basalt fibre reinforced plastics as energy-efficient structural reinforcements for
building constructions. The mechanical and thermal properties of basalt fibre reinforced polymer
(BFRP) composites with variable matrix formulations are investigated. The article considers macroand
microstructures of innovative BFRP. The investigations focus on fibre–matrix interactions with
different sizing formulations and their effect on the tensile strength, strain as well as modulus
of elasticity.
Precast concrete sandwich panels (PCSPs) are known for their good thermal, acoustic
and structural properties. Severe environmental demands can be met by PCSPs due to their use of
highly thermally insulating materials and non-metallic connectors. One of the main issues limiting
the wider use of sandwich walls in construction is their unknown fire resistance. Furthermore,
the actual behaviour of connectors and insulation in fire in terms of their mechanical performance
and their impact on fire spread and the fire resistance of walls is not fully understood. This paper
presents an experimental investigation on the structural and thermal behaviour of PCSPs with
mineral-wool insulation and glass-fiber-reinforced polymeric bar connectors coupling two concrete
wythes. Three full-size walls were tested following the REI certification test procedure for fire walls
under fire and vertical eccentric and post-fire mechanical impact load. The three test configurations
were adopted for the assessment of the connectors’ fire behaviour and its impact on the general
fire resistance of the walls. All the specimens met the REI 120-M criteria. The connectors did not
contribute to the fire’s spread and the integrity of the walls was maintained throughout the testing
time. This was also confirmed in the most unfavourable test configuration, in which some of the
connectors in the inner area of the wall were significantly damaged, and yet the structural connection
of the concrete wythes was maintained. The walls experienced heavy heat-induced thermal bowing.
The significant contribution of connectors to the stiffness of the wall during fire was observed and discussed.