CONCRETE & STONEWORK
Whether conventional or permeable , concrete block paving is particularly suited to well-established mechanised installation techniques . In essence , a hydraulically operated clamping system is used to lift a ‘ cluster ’ of concrete paving blocks – generally around 1 square metre in area and already in the required laying pattern . Clamps can be fitted to a variety of site equipment or form an integral part of dedicated machines designed for good site manoeuvrability .
Increased Productivity All kinds of block shapes and styles , including standard rectangular , can be machine laid in various patterns including herringbone which some manufacturers offer ready for machine laying . Productivity is comparable with asphalting operations and the ability to deploy a block laying machine and crew at short notice to meet ‘ just in time ’ demands on sizeable projects is a major advantage . But there are benefits in using the technology on modest sized projects , as well as major schemes . Faster installation means earlier completion and less operational downtime of the paved area – not forgetting that block paving can be used immediately after completion without curing times . Machine installation also makes it easier to achieve consistent accuracy and uniform joint widths . It is less tiring for operatives and also enables social distancing measures to be maintained on site . To maximise these efficiencies , installation contractors are adopting a similar mechanised approach to all site processes .
Safety and Efficiency The same concept can be applied to other precast concrete paving products to improve safety as well as efficiency . Concrete kerbs have been in use for around 70 years and concrete flag paving for even longer . Regulations have been in place for some time to protect workers from risks associated with musculoskeletal and upper limb disorders resulting from manual lifting and installation of these products . Elimination of manual lifting should be considered at the design stage so that kerbs and flags are always handled and laid mechanically using vacuum lifting gear , mechanical grabs or similar devices .
Another area where safety measures offer other cost and efficiency benefits is the elimination of cutting concrete paving products . Silica is a natural component found in many construction products : crystalline silica is found in sand , sandstone , granite and concrete . Health hazards can result from breathing in the fine dust of crystalline silica . But this risk can be eliminated when installing precast concrete paving blocks , flags and kerbs – either by removing the need to cut concrete products through careful design or by utilising safer cutting practices and equipment .
Modular by Nature It is important to remember that the key to attractive , durable , costeffective precast concrete paving is to optimise its modular nature , by dimensioning areas to minimise cutting and combining compatible products to avoid it . There are numerous techniques and special products readily available to help with this , as well as different styles of precast concrete kerbs , channels and other components .
Consideration of all the product alternatives and sizes available at the design stage , and careful setting out can generate real efficiencies and eliminate the need for cutting . As with any construction operation , the devil is in the detail – with edges , insertions , level changes and junctions within paving , which should not just be left to onsite operatives but resolved off-site within the design .
A guidance document on the detailed design and installation of modular concrete paving has just been published by Interpave , readily available – together with other guidelines and case studies – via : www . paving . org . uk
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