Transportation of construction materials. For the design and operating conditions of vehicles

In our country, from year to year, the industrial, energy, agriculture, and especially housing and cultural and community building. At his pace, efficiency, and the value directly affects a clear, high-quality work of Transport for transportation of building materials, structures and components. Nomenclature of building materials is very diverse. This bulk cargoes (gravel, sand, slag, crushed stone, gravel, etc.), wall materials (brick, brick, concrete, cinder blocks, panels), concrete products, metal structures, long cargo (farm, pipes, beams, boards, etc.), mortars (cement, liquid concrete, etc.), dusting goods (cement, lime), etc. Points of origin of building materials are primarily places of extraction, construction sites, warehouses, business building materials industry, destinations - the company building materials industry, warehouses, construction sites. Conditions of carriage of building materials heavy enough. At construction sites due to variability of the front work access roads and platforms for loading and unloading are unpaved. Limited size of the loading and unloading areas leads to the need to make loading and unloading often difficult to maneuver. Dust in the air during the dry season is high. Transport distance, depending on the type of cargo and other factors ranging from 1 to 40 km. Features of the cars in the building defines the following basic requirements for their design. In connection with a wide range of goods there is need for a different purpose of rolling stock: cars, trucks, cars and trailers, cement, rastvorovozov, panelevozov, fermovozov, trailers, heavy trucks, etc. x to the car-dump trucks used in construction must meet the following basic requirements. Their capacity and volume of the body should be established on the basis of collaborative environment to work effectively with an excavator. Due to heavy traffic conditions and anguish of loading and unloading places a maximum load capacity trucks shall not exceed 20 m. The dynamic factor in first gear should provide a reliable Hill climbing on departure from the pits. For ease of maneuvering in tight spaces increased requirements to the parameters of compactness. Car-body construction trucks destined for mortars, should not prevent them from splashing. Body trucks for the transport of viscous, adherent to the body loads, if necessary, be equipped with pneumatic and electric vibrators. Effective means is lining the inner surface of the body such materials to which viscous loads do not stick. Car-body trucks for the transport of concrete, equipped with a double bottom and a heating system exhaust gases from the engine, which prevents the "seizure" of concrete in the winter when low temperatures and sticking it to the bottom and sides. Additional bottom of the 2 devices for heating the body of the car-dump truck (Fig. 4.15) is placed on the welded to the main underbody a metal corners 3. It is welded to the core bottom and front board. The gap between primary and secondary closed head bent metal corners. In the space between them on the inlet nozzle 6 is fed exhaust gases of the engine. Metal corners create a kind of labyrinth, passing through which the exhaust gases heat the entire base area. When the car platform is lowered, the flange 7 pipe tight to the flange of the inlet pipe 8, 9 fixed to the frame the car and connected to the exhaust pipe 4. Flap in the exhaust pipe allows to override him, and then the exhaust gases enter the space between the bottom. Their production is carried out through the exhaust pipe 5. On trucks, construction workers, with a small length of haul (1 ... 4 km) and the absence of freight forwarders do not need to install a double cabin. Especially that single cab less metal and provides better visibility of the car, which is very important when working in cramped construction sites. Motors trucks must have a reinforced system of filtering the air entering the engine cylinders, must be equipped with ventilation system and the installation of filtering incoming air cab driver. In the construction of the widely adopted car-cement for bulk transportation of cement, a substantial share in overall transport of construction materials. Cement - pulverized goods deteriorate when wet, compresses for transport and has an abrasive, completely. Transportation of cement in hermetically sealed containers for special rolling stock ensures their safety during loading and unloading, transportation, and protecting the air basin from entering the atmosphere of harmful substances. Cement is a special train, consisting of truck tractors and semi-tank. Cement unloading system - air from the compressed air from a compressor, which is driven by a motor vehicle towing (Figure 4.16). Compressor 7 delivers compressed air through vlagomasloot-divider 8 to the diffuser 11, then through the valve 9 and line 6 to aerodnischu 14, and pipeline 4 via the valve 2 to the nozzle a discharge pipe 3. In the opposite direction of the cement can not move through valves 5 and 10. Aerodnische a tray, closed the porous layers of cotton cloth 13 laid on a metal grid 12. Penetrating through the grid and layers of tissue, compressed air crushes cement into small streams, and mingling with it, gives it fluidity. Going then through a discharge pipe 3 and a nozzle, the air drags the cement and delivers it through a hose to the destination. Transportation of ready-mixed concrete, in addition to ordinary cars, trucks, cars may be carried out, concrete mixers, providing a continuous mixing of the concrete mixture or preparation of the dry ingredients and water while in motion. The design of the car-mixer (Fig. 4.17) consists of a chassis of the car, the mixing drum 2, loading-unloading device 3, a tank with equipment for feed and water metering, drive 4 mixing drum, which is a tank with a built in his lobes. Mixing drum drive can be mechanically from an independent internal combustion engine or hydraulic with power takeoff from the motor vehicle or stand-alone engine. The volume of the finished batch of concrete mixers on the MAZ is 2,5 m3, on KrAZ - 3,2 m3. Foreign-produced cars mixers big performance on the chassis of trailers (the volume of mixing them up to 10 m3). Cars-mixers are used to transport concrete over long distances. When mass transport ready-mixed concrete with a concrete plants to construction sites at a distance of up to 20 ... 30 km using conventional dump trucks. Under the terms of transportation and construction of reinforced concrete products can be divided into the following groups: details and design of small size, wall panels and walls, trusses and beams, three-dimensional elements (block section santehkabiny). Transportation of parts and structures of small dimensions is carried on board vehicles and road trains, consisting of cars, trucks and trailers. In the carriage of the wall panels and partitions to observe a number of conditions: to avoid damage the panels should be installed vertically or at an angle (not more than 8 ... 12 ° from vertical) and securely attached, placing panels in transit should ensure that they are unloaded in any order and, finally, when Transport of coated panels is necessary to exclude the possibility of friction between them. For the transport of panels used train-panelevozy consisting of cars, trucks and trailers. Distinguish panelevozy: spinal, in which panels are placed on both sides of the spatial carrier farm, located along the longitudinal axis of the train; cassette having a cassette to accommodate the panels, frame, having a frame on which a vertically mounted cassette. By way of loading semi-panelevozy divided into panelevozy with central loading, side-loading and the central and lateral load at the same time (Figure 4.18). We shall be operated semi-truss panelevozy center-farm - panelevoz spinal and lateral plane carrying the farm-cassette panelevoz. Basic requirements for the design panelevozov: fitness for the carriage of panels in a vertical or close to the situation, a small loading height (not more than 0,8 m), which provides transportation of panels with a transport height at not more than 3,8 m, the ability to transfer panels in a horizontal position during unloading; size cartridges or loading docks shall provide loading panelevozov with maximum use of capacity and convenience for loading and unloading, experimental papers, staffed by hydraulic supports (unilateral or bilateral action) with the management of the cab tractor, semi-panelevozy with enlarged base should be articulated bogie system powered by a car-tractor; protection panels on the mechanical and dirt during transportation. For transportation is widely used in construction of industrial buildings and structures of reinforced concrete trusses, which reaches a length of 30 m and more, using train-fermovozy. To transport this type of load characterized by deterioration of the maneuverability of the vehicle stability during cornering and on bad roads, the need for exceptions to the perception of the farm effort twisting and buckling, transmitted to the frame of the vehicle when driving on rough roads. The latter may not apply to farm arched up to 18 m, which may be transported on trains, consisting of a car-tractor and trailer-dissolution. Modern "fermovozy represent semi-skeletal structure, cassette type. The main requirements for them: to ensure the possibility of transport of farms in the position, performance on low-bed trailer with a loading height of the scheme not more than 0,7 m; equipment truck trailer steer.