Slip Form Paving
Slip form technology is one of the revolutionary cutting edge technologies in building and construction industry. The slip form paver greatly improves the quality of pavements and reduces labor costs.
Essential Features of Slip Form Paving Machinery
The machine utilizes low slump concrete that has limited flow and therefore tends to remain at the same place without the need for erected concrete formwork. Therefore, the placement, consolidation and surface finish are easily done.
The machine works using the extrusion process. The extruders squeeze concrete in the mold that has the predetermined shape.
The squeezing action forms and consolidates the concrete. The slip form paver provides vertical and horizontal force. The weight of the machine pressers the concrete against the mold sides from the top. The horizontal forces are created by the tapered side forms. In addition the continuous movement of the machine presses the confined concrete. The vibration process fluidizes the materials enabling them to spread and consolidate.
The most critical elements of this machine are; the auger or a paddle which uniformly distributes the concrete, the hydraulic powered tamper bar for consolidation and the profile pan which is the finish tool. In addition, the internal vibration created by a set of hydraulic vibrators is critical since it fluidizes the concrete allowing it to spread evenly, removes internal voids and allows slipping which is critical in slip form equipment.
The paving width is of critical importance as it determines the span of the road or pavement. The width is defined as distance between 2 crawler tracks. Typical machine widths range from 2, 5, 8 meters while larger ones can go up to 18 meters width.
Other critical features of these machines include: number of hydraulic vibrators that range from 8, 16, 24 onwards, the hydraulic circuits, high efficient diesel engine, power washing mechanism, hydraulic adjustable sides, hydraulic steering , fully operator panels with sophisticated controls among other features.
Application of Slip Form Technology in Large Paving Projects
This technology is suitable in large construction projects for bridges, roads, pavements and open water channels. Unlike other paving technologies that require erecting formwork, pouring concrete, ramming using vibrators and curing; this method only uses a machine that continuously forms the structures.
Advantage of Slip Form Technology
These machines are the most ideal for large-scale pavements such as those in airports and highways. Since these tracks are subjected to extremely heavy pressure and loads, the concrete must be made without irregularities.
Unlike prefabricated concrete, slip form can be made to any profile and hence suitable for sewage and water channels, safety barriers, raised edges at road side. Paving moulds can be made to customized shapes that produce a variety of low tolerance, smooth surface and easy to maintain concrete pavements.
Some machines have the capabilities of double layer forming as opposed to single layer which saves time.
They are economical as it uses small diesel engine to provide power which is amplified by hydraulic system. This is also environmentally friendly and the operator safety and ergonomics are guaranteed.
Demand and Forecast for Slip Form Technology
As industrialization and commercialization continue to increase, more pavement and roads are required in commercial, residential and industrial establishments. This is set to increase the demand for these heavy duty concrete machines by construction companies which in turn use them or hire them to other firms.