Qualify the finished surface, not just the grain
Silica sand can contribute to the texture of a pedestrian coating. However, a material sheet giving a particle-size distribution does not demonstrate the slip resistance of the floor. Between the delivered grain and the surface in use lie the binder, application, finishing coats, curing, cleaning and wear. Qualification must follow this chain.
For a project in Rabat or Salé, begin by identifying the area: building entrance, outdoor walkway, covered passage, ramp or place exposed to water. The institutional profile of Rabat-Salé-Kénitra documents a region with diverse activities and projects 1. It does not establish a uniform coating requirement or local particle-size prescription. Each site remains defined by its actual use.
This dossier proposes a texture-selection and acceptance method. It distinguishes the sand property, coating-system performance and walking conditions. This distinction avoids purchasing solely on the expression “anti-slip sand”, which describes neither the finished product nor its testing protocol.
1. Describe the walking situations to reproduce
Before requesting a fraction, record the conditions of use. Will people wear shoes or walk barefoot? Can water remain on the surface? Is there a slope, a transition between materials or an area where people change direction? These questions guide the testing programme and design of the qualification panel.
HSE documentation distinguishes measurement conditions and equipment, including sliders corresponding to different walking situations 2. A value obtained on a dry surface therefore does not demonstrate the behaviour of that surface when wet. The dossier must identify the condition actually evaluated.
Bring together the functions concerned before testing: design, application, maintenance and acceptance. Maintenance knows the cleaning products and operations; the applicator knows the installation constraints; the designer knows the intended uses. A specification developed without this exchange can succeed on a panel while becoming difficult to preserve on site.
2. Separate sand size from surface relief
Grading describes grain size. Surface relief describes the arrangement after application. A grain can be buried, partly exposed, covered by a finishing coat or detached during use. Two formulations using the same sand can therefore produce different surfaces.
To compare fractions, request the actual grading curve rather than a commercial range alone. The fine-grain proportion, upper end of the distribution and grain shape can influence the applied finish. Also record whether the material is dry or wet and how it was prepared. The purpose is to reproduce the selected panel with a defined material.
HSE presents microroughness as an indicator that can supplement slip assessment, with instrumental and interpretation limitations 4. This microroughness is not the nominal diameter of a sand. Directly converting a fraction into a slip classification would remove the essential step: observing and measuring the finished surface.
3. Fix the application system before comparing variants
Identify the substrate, its preparation, the binder, the method of incorporating sand and subsequent coats. In a broadcast system, record the amount applied and the amount removed after curing. In a premixed system, record masses and the dispersion procedure. These are two different methods of introducing the material.
Define system thickness or consumption according to the manufacturer’s instructions. This article does not propose a universal sand or resin dosage. An amount suitable for one product can prevent application or change another product’s result. The trial must therefore concern an identified combination, rather than sand separated from its binder.
Record the relevant temperatures and delays while manufacturing the panels. Do not compare one fraction prepared on a dry substrate with another applied under different conditions when the objective is to isolate grading. Useful data are those allowing the panel to be made again, rather than merely providing an attractive description of its appearance.
4. Build a small comparative panel programme
Start with a reference and a limited number of variants. Change one main factor, such as the sand fraction, while retaining the rest of the system. If the finishing coat is then modified, identify this second stage as a new trial. A readable comparison is more valuable than many panels whose variables all change together.
Give each panel a code. Associate it with its material lot, masses, preparation conditions and curing stages. Arrange preparation repeats where the intention is to check application reproducibility. Measuring several places on one panel describes its surface; it does not replace several independent preparations.
Retain a reference area if the programme includes ageing or cleaning. Photographs help track appearance but do not replace the planned measurements. Present images with the same lighting, scale and framing. Changing the photographic method can create the impression of a texture change that has not occurred.
5. Define tests and interpretation before measuring
Cerema describes several instruments for characterising pedestrian walkways, including the friction pendulum, giving different information on adhesion and texture 3. Equipment selection must match the question being investigated. Two indicators with similar names are not necessarily interchangeable.
Ask the laboratory to identify the method, surface preparation, slider or contact used, directions and dry or wet condition. Also define how variation between locations will be treated. A satisfactory average can hide one location substantially different from the others. A measurement map remains important for an applied surface.
The foreign guides cited are technical references, rather than a presentation of Moroccan requirements. Include the agreed protocol and contractual criteria in the project specification. A commercial class without a method or conditions leaves too much room for interpretation. Acceptance should use the same definitions as qualification.
6. Examine grain retention
An initial texture is useful only if grains remain properly incorporated in the coating. Plan surface observation after the selected project stresses. Look for polished areas, released grains, detachment and finishing-coat changes. The result should connect relief with system integrity.
Do not confuse grains removed after installation with those lost during use. A broadcast system can require removal of excess material before entering service. This operation forms part of final preparation. The measured condition should represent the completed coating, with cleaning and finishing stages performed.
Describe the selected wear method. A laboratory test represents a defined stress, rather than an automatic service-life calendar. To draw conclusions, compare variants subjected to the same programme. Avoid predicting years of performance from a cycle count without a demonstrated correlation for the system and use concerned.
7. Include cleaning in qualification
A textured surface can retain dirt in its recesses. The cleaning arrangement must be compatible with its relief, binder and use. Describe products, tools, any rinsing and drying. The aim is to qualify a maintainable system, rather than a panel that is merely clean when leaving the laboratory.
Reproduce the planned cleaning stages on the panels, then observe appearance and measure again according to the selected programme. Identify possible residues rather than attributing every change to the sand. A film left by a product or a polishing operation can change surface condition without changing the incorporated grading.
Have the procedure assessed by the team that will perform it. If it requires unavailable equipment or a time incompatible with operation, the solution can be technically interesting but operationally fragile. Record permitted changes in the maintenance sheet. Replacing a product or tool without monitoring can modify the qualified surface.
8. Check comfort and transitions
Texture should be assessed with the walkway’s other qualities: flatness, continuity, drainage and user comfort. Cerema connects material choices with pedestrian adhesion and comfort 3. Sand selection alone does not resolve a level discontinuity or poor water evacuation.
Include a representative transition in the trial area when it forms part of the project. The difference between two surfaces can matter as much as their individual behaviour. Document connections, joints and changes of direction. A completely uniform panel cannot examine these application details.
Do not turn a tactile impression into a test result. User feedback helps compare comfort, appearance and ease of movement; it should not be presented as a friction coefficient. Retain both types of feedback in the dossier: technical measurements and use observations, each with its own method.
9. Arrange acceptance of the coating actually installed
Panel qualification is one stage. Acceptance examines the site surface. Divide the site into coherent areas according to substrate, installation date and application conditions. Plan locations in ordinary areas and sensitive details, rather than selecting only places that look most uniform.
Record the sand and binder lots associated with the areas. If an anomaly appears, this traceability helps distinguish a material deviation from application variation. Also retain the applicator’s observations: interruptions, restarts, temperature changes or finishing difficulties. These provide context for a local measurement.
Before making any correction, describe the deviation and its extent. A treatment applied everywhere to solve a local defect can modify areas that were already satisfactory. The repair itself should be checked under an appropriate programme. Keep the connection between observation, action and the result after action, instead of replacing the initial report.
10. Plan monitoring after entry into service
Select monitoring locations: an exposed entrance, a busy section, a cleaning area and a less heavily used portion. Comparison between these places helps interpret change. Define frequency in relation to operating conditions and observations, without assigning a universal renewal interval to the sand.
After changing cleaning, repairing the surface or changing its use, reassess the areas concerned. The coating assessed at acceptance is not necessarily identical to that present after these interventions. Monitoring should concern its actual condition, using the same location references and a compatible measurement method.
The final dossier brings together material, system, tests, selected panel, acceptance and maintenance. Our silica-sand page complements this approach when preparing general aggregate characteristics. The final decision concerns a reproducible, maintained texture whose performance has been assessed under explicitly defined conditions.
11. Read a comparison without confusing its stages
Consider two panels made with the same sand and binder but different finishing coats. This is a reasoning example, rather than a campaign performed by Minerallum. If measurements differ, the initial conclusion concerns the two completed systems. It does not establish that sand in the second panel is intrinsically less suitable, because the material is identical.
The report should retain the preparation of each panel and its condition after finishing. Compare grain exposure, applied masses and operations performed. If a coat covers more of the texture, this becomes a hypothesis for explaining the difference. Verification can include another preparation in which only that stage changes. The aim is to connect the result with a reproducible action.
Now suppose a panel gives a satisfactory result before cleaning and a different result after cleaning. Three questions must be separated: has the surface changed, does a residue remain, and are measurement conditions comparable? These questions cannot be resolved by automatically changing grading. The cleaning record and surface preparation become essential parts of the examination.
Retain an untreated panel and, if necessary, prepare an independent repeat of cleaning. Compare observations with measurements using the same protocol. If the change comes from a maintenance product or operation, correcting the procedure can be more relevant than modifying the material. If it comes from grain loss, analysis should also examine how the grains are incorporated in the system.
Finally, when a site area differs from the accepted panel, first examine that area: substrate, lots, consumption, curing and finishing. The panel represents a known preparation; the site area represents an application that needs documenting. The conclusion must specify the extent of the deviation, because a local difference does not establish that the whole coating behaves identically.
This staged interpretation facilitates discussions with the applicator and laboratory. It turns a vague judgement of roughness into verifiable questions: which preparation, which surface condition, which stress and which result? It also avoids asking the sand supplier for a guarantee that actually concerns the complete system. The sand remains a characterised component; acceptance concerns the coating and its use.
In the final material enquiry, specify the selected fractions, their identification and preparation parameters that produced the accepted panel. Include the grading curve and retain a reference portion when the programme requires one. The next incoming delivery can then be compared with a documented requirement. A change of commercial designation should not erase the characteristics used to qualify the system.