Legal weight limits for commercial vehicles, which vary from state to state, are posted per axle. To be clear, if your job or safety depends on knowing this stuff, please study a more comprehensive rundown. What is that last axle doing all the way up there?
It, too, is ostensibly for weight-bearing but largely for legality. In this scenario optimized for easy math, your dumper bucket can hold cubic feet of whatever. Now you can bear 50, pounds, and the iron can be taken to wherever it needs to go.
Once you dump it, you can retract your drop axles to save on tire wear, fuel, and toll bills. And most importantly, the truck will be much easier to drive with fewer wheels on the road. Venture trucks are a type of truck on a skateboard, that hold on the wheels. Venture trucks are not necessarily bad, this is simply an opinion. Wheels dont make a skateboard easier to turn on the skateboard trucks do that.
Regular trucks don't have as much tread as ice road trucks. Ice road trucks have strong steel frames and ice wheels as well. Of Course Not! You need to plant a hot-wheels toy car in the ground, do the shimmy on top of it, and maybe tomorrow you will have your own Range-Rover! Log in.
Tractors and Farm Equipment. Construction Tools. See Answer. Best Answer. Study guides. Q: Why do concrete trucks have wheels on top? Write your answer Related questions. Roger asked big trucks to deliver 32 wheels and small trucks to deliver 16 wheels. Can you use any trucks and wheels for a skateboard? Will any skateboard trucks fit any skateboard wheels? How many tires does a Boeing have? Function of front wheels on forklift? What are the parts on skateboards called? What vehicles have seventeen wheels?
Why do big trucks have eight wheels instead of four wheels? Why are the rear wheels in trucks broader than the front wheels? Which truck is best known for its big wheels? What board adjustment is best on Skate 2 with trucks and wheels? In baking terms, the difference between concrete and cement is the difference between flour and a loaf of bread. Concrete is a generic term for a mix of aggregate -- usually stone or gravel, water and cement.
Modern cement is a complex blend of finely ground minerals, and goes by the generic name of "portland. Stephen Stepanian developed and applied to patent the first motorized transit mixer in , in an effort to replace the horse-drawn concrete mixer used at the time. Wooden paddles churned the mixture as the cart wheels turned, but the design was of limited use -- it was cumbersome and slow. The same, however, could be said of the engines and trucks during that period. But by the s, engines and truck-frame construction caught up to the need for a rugged vehicle capable of hauling thousands of pounds of wet, or unset, concrete.
As the building boom following World War II went into full swing, mixer trucks came into their own. The large drum mixer seen on roads today hasn't changed much from Stepanian's vision of a better concrete hauler. Mobile transit mixers are a mix-and-match selection of engine, truck frame and rotating mixer. The mixer is similar, though larger in scale, than the smaller ones found on construction sites.
A large motor , separate from the engine, rotates the drum on the truck body, and a series of blades or a screw powered by the same motor keeps the aggregate, water and cement in constant motion. This keeps the premixed concrete from setting, though the clock is often ticking to get the load to the construction site, road section or parking lot. Most cement manufacturers suggest keeping the time between mixing and pouring to 90 minutes at most.
It's even better to get it to the site in less than an hour. As technology has changed, so has the basic mixer design. While many transit mixers still have rotating drums, most don't simply pick up a load of wet cement and transport it. The few that still do head mostly to road sites where it's possible to pour the mixture immediately.
Most transit mixers have a separate water tank in the truck. The spinning drum keeps the dry ingredients, aggregate and cement mixing during most of the trip. When the driver is within a few miles of the site, water is added to create concrete fresh for delivery. This is considered "batch" delivery of ready-mixed concrete, mixing ingredients off site and trucking them where they're needed. Advances in technology have made it possible to mix concrete at the job site, though transit mixers are still the workhorse of the field.
Volumetric and metered mixers are becoming more common. Both types are essentially on-site custom concrete plants. Separate holding tanks of aggregate, cement and water are contained in one truck with a computer hooked to augers and pumps. At the site, the customer can order a specific type of concrete there are more than a dozen that can be mixed by the truck.
Volumetric and metered mixers are often used during high-rise construction and can be paired with pumper trucks to deliver concrete more than 15 stories above the ground. Some form of concrete -- the mix of a binder, aggregate and water -- has existed since the dynasties of the Egyptian pharaohs when water, sand and lime were mixed to use as mortar in building sections of the pyramids.
Romans also used a form of concrete in constructing their aqueducts, the Coliseum and other major constructions. Scientists in the s began experimenting and perfecting hydraulic cement , which is what the construction industry still uses today.
The name for portland cement came from the Isle of Portland, off the English coast, where deposits of the mineral components used in modern concrete were first found and chemically isolated. By , Thomas Edison was experimenting with building pre-cast concrete houses in Union, N. Most of those houses are still standing and being used. Then there are the famed Hoover and Grand Coulee dams, built in , that stand among the wonders of the world.
While concrete comes in bewildering array of types, one thing is certain -- it's heavy. A large batch of concrete can weigh more than 30, pounds 13, kilograms , not counting the weight of the truck itself, anywhere from 10, to 30, pounds 4, to 13, kilograms.
For a truck to haul that weight, it has to be powerful. And to get that load over the rough terrain of a construction site, the truck has to be tough. The trucks come in three separate parts -- engine , frame and mixer. Most truck companies provide the engine and frame, with amenities ranging from sleeper cab to computer navigation.
The mixer, or volumetric plant , is added on at a later time. Each company has specific wants and needs and requires a truck tailored to those. For example, some may need a truck with a heavier engine and a lighter drum, which could be removed at a later time and turned into a trash hauler with a few modifications.
Most truck engines range from to horsepower , depending on the application. Some companies offer engines with more than horsepower. Horsepower is a measure of power , an engine's "oomph," in other words. The "oomph" is usually supplied by a diesel engine, most commonly manufactured by Cummins or Caterpillar.
Diesel engines produce more torque at lower engine RPM than a similar gas engine, making them ideal for low-speed, high-power applications like towing or hauling. Diesels are also preferred for their longevity -- many can go for a million miles 1,, kilometers or more with routine maintenance -- as well as their ruggedness. Unlike gas engines, diesel engines operate using compression ignition and require a heavy engine block to withstand the tremendous forces at play inside them. That same compression ignition means the engine function with a higher compression ratio within the cylinders, thereby producing more power.
That power is translated to torque, or rotational power, through special gearing in the transmission -- mixers have anywhere from 7 to 18 gears and can be manual or automatic, and differentials. Most concrete trucks produce anywhere from 1, to 3, foot-pounds of torque.
0コメント