Glass reinforced concrete represents a composite material consisting of fine-grained concrete (matrix) and dispersion reinforced with short glass fibers. Thus, glass reinforced concrete (or GRC) combines the typical of the conventional concrete high compressive strength with extreme flexibility and tensility (4-5 times higher than in concrete), strength (10-15 times higher) and frost resistance (more than 300 cycles).
This is an environmentally friendly material that does not contain harmful ingredients and belongs to the category of non-combustible materials. Glass reinforced concrete offers increased waterproofness and a high degree of adhesion to plain concrete, boasting high resistance to cracking at the same time. Easily molded, acquiring complex spatial shapes with GRC is a walk in the park mission, plus the material exactly replicates the tiniest details on the surface. Moreover, GRC products have a small cross-section (ranging from 6 to 20 mm) and are considerably lighter in comparison with the products of conventional concrete.
Apart from the purely functional properties, a noteworthy GRC feature is an increased architectural expression, as well as extraordinary plasticity. It can play a variety of colors and shades, transmit various textures to recreate the most unexpected for stone material shape and form. The magnificent set of properties predefined the leadership in precast-monolithic and other types of construction throughout the world.
GRC bribes the experts with its versatility and diversity of application spheres, from wall panels for building facades and architectural and decorative details to elements of permanent formwork in bridge and anti-noise barriers. In addition, glass reinforced concrete is widely utilised in installing roofing and waterproofing.
The nomenclature of test rigs is extensive enough, and, therefore, the equipment line-up is pretty diverse. Virtually all the manufactured products pass a particular control, characterised by various complexity and applied in serial and mass production. More importance is attached to test rigs in individual, pilot and small-scale production and (air tooling in particular).
A normal test cycle can be divided into three stages. The first stage, test preparation, implies defining of the objectives; selecting or designing the required test equipment and its manufacture; measuring equipment selection; products preparation (locations designed to accommodate the equipment revision); preparing technical documentation. The second stage is about actual test, and the third one is processing experimental data and the test results formulation.
When testing complex products or systems, it is necessary to receive and process a large amount of information on the various parameters (the total number of parameters may equal several thousands of items). The laborious process rests on the shoulders of a large amount of qualified technical workers. Thus, the use of information-measuring systems for automated test rigs is a challenge yet to be leveled.
In addition, during testing the equipment is adjusted (i.e. regulate its parameters), which implies managing the testing process. To perform the operations mentioned above, test rigs are equipped with automated systems.
Natural rigs testing is particularly vital in various researches conduction and upgrades development. Despite the fact that they extend the process of designing, making it more costly at the same time, the procedures guarantee a high level of reliability and optimality of methods used.
The growing demand of both industrial towns and large cities in carports, caused by the high population density in the urban areas, throw designers together with a good number of challenges. The main objectives set to car park ventilation professionals are typically the following:
- Maintain the acceptable indoor air parameters
- Ensure decent fire resistance
- Implement an environment-friendly system
Covered parking facilities are usually located below the ground level and require the installation of mechanical ventilation in nine cases out of ten. Semi-covered parking constructions, as a rule, are comprised of frames with multiple floors, though a roof and exterior walls may be partially or completely absent. This is where a natural or mixed ventilation system can be installed (a combination of natural and mechanical systems can also be installed for sites with a large floor area).
Closed car park ventilation system performs the following functions:
- Maintains the allowable concentration of carbon monoxide (CO)
- prevents the formation of explosive concentrations of flammable gases
The main factor determining the characteristics of a future parking ventilation system is the approximate number of cars serviced on a daily basis. This number is oftentimes determined by the type of construction, which represents the carport. As a rule, apartment buildings and shopping centers adopt the condition of constant and distributed car use, while the number of moving vehicles varies from 3% to 5% of the total number of cars. The situation is different in parking lots of sports facilities, concert halls, airports and etc. Here, the number of vehicles in simultaneous motion equals 15-20% during peak hours or during the hours that coincide with the beginning or the end of the business day.