With ever-rising steel prices, it makes great economic sense to install concrete platform weighbridges. Apart from low costs, it offers high strength and is virtually maintenance free – requiring no painting every year. Its life is 100 years as compared to that of 15 years of a typical steel platform. Due to the advantages of concrete platforms, the developed world has been using them for over 30 years. In Europe 95% of electronic weigh bridges are made with concrete platform.
As the platform gets longer, cost saving increases. Modern day transportation is moving towards using longer trucks and trailers. MNC truck manufacturers, such as Volvo, who have started manufacturing in India, are introducing longer models which are capable of carrying heavier payloads. The concrete platform weighbridge can bear heavier loads. That is why all modern bridges that one sees on the city roads are either concrete or composite.
A heavily loaded truck entering the weigh bridge gives heavy jerks on braking. Vibration thus caused, reduces the life and accuracy of the load cell and thus needs to be reduced to minimum. Vibration is much more in the case of steel as compared to concrete as it absorbs vibration.
The cost of material required for construction of concrete platform is approximately 40% less than that of steel platform.
Material quality :
Quality of steel is always a suspect owing to the presence of a number of local companies which make cheaper and inferior quality steel, thereby decreasing the life & performance of steel components over time whereas the onsite construction of concrete weigh bridges helps monitor quality capacity.
The construction of the concrete platform is designed so as to carry a load upto 100+ tons by using heavy duty load cells. Hence the capacity of the weighbridge can easily be enhanced up to 100 tons, if required, without incurring any extra cost whereas in the case of steel platform weighbridge, the capacity cannot be increased with the existing steel structure. Joints & plates of higher proportions would be required. Add to all this the cost of the cells which will need to be replaced.
Due to rattling of steel structure, nuts & bolts get loosened thereby requiring periodic tightening. Also steel gets rusted due to changes in the environment over a period. Being a totally RCC structure, there is no rusting of components in concrete platforms hence they are totally maintenance free.
Steel being flexible tends to bend & rattles when the truck comes onto the platform. Due to this there is a lateral pull of the load cells wherein ideally the load should be transferred vertically. The concrete platform is a rigid monolithic structure. As soon as the vehicle comes over the platform, the load gets distributed to all 6-load cells.
Steel structure being lighter by weight than the gross load of the vehicle coming on the platform, a cantilever effect takes place with inverse forces taking place at the ends thereby having a tendency to twist the steel structure & causing weighing errors. The concrete platform being a heavy mass has more stability. Hence, no inverse forces take place in the platform.
Steel structured weigh bridges are prone to electro-static charge & high electric field caused by strong winds & lightening which may damage the weighing instrumentation & load cells. The platform of concrete structure is totally immune to such environmental harshness, thereby the system more stable & maintenance free.
The steel platform/girder structure gets weak due to rusting & loosening of nuts etc. The top plate & joints have a bending effect after few years. The concrete platform has a very long life and no bending effect takes place.
The steel structured weighbridge is fabricated at works & is transported to site by truck for installation on the foundation thus incurring heavy transportation costs. The construction of the concrete platform is cast on the foundation, at site, thus saving on transportation.
Vehicle movement :
Vehicle movement & sudden braking tends to break the anti-skid strips welded onto the steel platform requiring re-welding of the strips by dismantling the load cells, thus rendering the weighbridge out of use for some time. In the case of concrete platform weigh-bridges, vehicle movement is arrested due to rough surface of the concrete platform.