ARCHITECTURAL FLOORING IN WASHED GRAVEL FOR PEDESTRIAN AND URBAN WAYS

TECHNICAL SPECIFICATIONS

Supply and installation of an architectural flooring (such as FLOORTECH PRERIT by AZICHEM srl), performed using a concrete with high durability.

To concrete, with a minimum strength of 30 N/mm², (Class 25/30 according to UNI EN 206.1), made with local aggregates rounded or angular (or with aggregates of different types and origin to be calculated separately) and Portland cement Type I or Type II / A-LL 32.5 R or 42.5 R composite (gray or white), pigmented or not pigmented with synthetic iron oxides (type PROTECH OXICROM  by AZICHEM srl), will be added both a multi-purpose premixed powder (type PRERIT COMPOUND of AZICHEM srl), specifically studied for the realization of this type of flooring made up of a peculiar and balanced mixture of reactive microsilicate-based fillers, multi-filament polypropylene micro-fibers, aerating, fluidizing and stabilizing agents, and polypropylene fibers (like READYMESH PM-180 of AZICHEM srl) with a length of 18 mm.

The above additions are aimed at achieving the necessary cohesion increases, fresh conglomerate, stability to atmospheric and aggressive agents, resistance to freeze/thaw cycles, resistance to abrasion, cracking and shocks, to allow the elimination of the usual electro-welded mesh, where not contemplated by design.

INDICATIVE MIX DESIGN FOR THE PACKAGING OF 1 CUBE OF SPECIFIC CONCRETE FOR THE PERFORMANCE OF ARCHITECTURAL FLOORINGS IN WASHED GRAVEL:

  • Cement Type II / A-LL 32.5 R (gray or white): 350-450 kg
  • Clean and selected aggregates (rounded or angular) diam. 6-12 mm (approximately): about 1500 kg
  • Clean and selected sand diam. 0-3 mm (approximately): about 100 kg
  • PRERIT COMPOUND (multifunctional additive): 25 kg
  • PROTECH OXICROM (synthetic iron oxide in the chosen color): 15-25 kg
  • READYMESH PM-180 (18 mm multifilament polypropylene fibers): 0.5-1 kg
  • Water (as required): About 250 lt
  • TOTAL MIXTURE: Approximately 2300 kg

The flooring, with a total thickness of 15 cm (10 cm of base concrete + 5 cm of washed gravel concrete flooring) or of a different thickness indicated by the works supervisor according to the final destination of the work, must be put in place after the creation of a substrate in concrete or perfectly compacted soil and, in any case, appropriately calculated according to the final destination of the work (work to be calculated separately), with subsequent positioning of the expansion joints and/or any inserts constituting the architectural motif according to the provisions of the Legislative Decree (to be calculated separately), and appropriate protection of curbs, wainscoting and any other architectural element that could be contaminated during the laying and processing of the flooring, to be carried out by applying suitable coatings or specific taping.

The installation will take place in the fields previously set up according to the following phases:

  • At the end of the laying, spreading and smoothing operations by hand of the concrete, avoiding any type of vibration or stress that could induce the sinking of the aggregates, a uniform layer will be sprayed with a suitable low-pressure pump (manual or electric) variable from 100 to 250 gr/m² (based on the quality of the concrete used and the weather conditions present at the time of writing), a surface setting deactivator (type PRERIT SOLUTIONof AZICHEM srl), based on chelating polysaccharides consisting of molecules of aldehydes and hydroxyl groups, certified free from harmful effects for the users and the environment, with the function of conveniently retarding the hardening of the cementitious surface matrix of the concrete and at the same time act as an anti-evaporation protection.
  • Within 24 hours, depending on the conditions of humidity, temperature, quantity and class of cement used (with an outside temperature between 18 and 23 degrees, the ideal time for washing is about 6-8 hours), the surfaces of concrete smoothed and treated with setting retarder must be washed with a cold water pressure washer, to show the aggregates.
  • The surface of the flooring, once dry, will be treated by spraying about 100 g/m² of suitable consolidating, water-repellent, anti-dust, based on lithium silicates, (type QL NANO LITHIUM SALT RESISTANTby AZICHEM srl), depending on the atmosphere of exposure and service, however characterized by a high protection and curing effect, able to significantly increase the resistance to abrasion, freeze-thaw cycles and de-icing salts, where present, as well as the overall durability of the works, without determining any criticality any in terms of possible delaminations.
  • Depending on the size of the paved area and its geometric conformation, suitable expansion and fractionation joints must be made to be adequately sealed. The correct sizing of the sealing section must include a width of 7-12 mm and a depth equal to ¼-1/5 of the thickness of the flooring. In order to prevent the sealant from slipping on the bottom of the joint and to correctly size its depth, a suitable compressible non-stick compressed expanded polyethylene foam cord must be installed in the joint seat (type FILTENE FONDOGIUNTO 15 by AZICHEM srl), having a diameter at least 20% higher than the width of the joint. To perfectly delimit the seal, the joints will be taped with adhesive paper tape. The joints must be sealed by extruding a suitable single-component sealant based on hygro-hardeningaromatic polyurethane resins resistant to water, oil and hydrocarbons, aviation gasoline (such as PROTECH SIGILFLEX MONO  by AZICHEM srl), after careful cleaning and removal of dust from the joint seat by means of compressed air. Flattening to remove excess parts and immediately smooth the sealant in the joint will be done with a metal spatula slightly moistened with soap and water. Once the operations are complete, the adhesive paper tape will be removed.

INCLUDED IN THE PRICE:

  • The supply and installation of the complete system.

EXCLUDED FROM THE PRICE:

  • The use of white cement type II A-LL 32.5 R or 42.5 R,
  • Pigmentation based on synthetic iron oxides,
  • The preparation of the base concrete,
  • The preparation of the perimeter containment curbs,
  • Possible reinforcements with electro-welded meshes,
  • Any inserts making up the architectural motif,
  • All work not included in the specifications.

 PLEASE NOTE:

  • The packaging, the laying of the cortical concrete designed with mix-design characteristics, type of cement and color, pigmentation, nature and color of the aggregates, must be accepted by the works supervisor after the realization of samples.
  • All the components of the concrete (aggregates, cements, additives, etc.) must comply with the regulations in force and be supplied by a company certified in accordance with ISO 9001: 2015, so that the finished work is carried out in perfect working order.