Damage types, the correct repair sequence, product categories, and why so many concrete repairs fail early — everything you need to specify with confidence.
Most concrete repair failures in our experience aren't caused by using the wrong product — they're caused by skipping or rushing a step in the sequence. Spalling comes back when corroded steel isn't properly primed before the patch goes on, or when a repair mortar is placed without a bonding coat and simply sits on top of the substrate until it debonds.
Botswana's exposed concrete — parking structures, balconies, water tanks, industrial floors, bridges and infrastructure — deals with UV exposure, thermal cycling between hot days and cool nights, and in some cases carbonation and chloride exposure that accelerates steel corrosion. This guide covers what to know before you specify or carry out a repair.
Correct diagnosis of the damage type comes before product selection — treating the wrong problem is a common cause of a repair not lasting.
Concrete breaking away in chunks, almost always caused by corroding reinforcing steel expanding inside the concrete and cracking it from within. Common on balconies, parapets, columns and beams exposed to weather.
Steel reinforcement rusting due to carbonation of the surrounding concrete or chloride ingress, reducing the steel's cross-section and generating the expansive rust that drives spalling. Must be treated before any cosmetic repair.
Ranges from fine, cosmetic shrinkage cracks to structural cracks indicating movement, overload or settlement. Active or structural cracks need engineering assessment before a repair product is chosen.
Voids and gaps in the concrete surface caused by poor compaction during the original pour, leaving a porous, weak zone that needs to be broken out and reinstated rather than skimmed over.
Gradual loss of the concrete surface from abrasion, chemical attack or aggressive cleaning, common on industrial floors and requiring a topping or hardener rather than a structural repair mortar.
General principles apply across most structural concrete repairs, though exact products and coverage rates vary by application.
Identifying the extent of damage and breaking out loose, weak or contaminated concrete back to sound material, with a clean edge rather than a feathered one.
Exposed reinforcing steel is cleaned back to bright metal and primed with an anti-corrosion coating before any repair mortar is applied — skipping this step is the single most common cause of repeat spalling.
A bonding agent is applied to the prepared substrate to ensure the new repair material properly adheres, rather than simply sitting on top of the old concrete.
The repair mortar or micro-concrete is applied and built up to match the original profile, using a product matched to the section depth and exposure.
The repaired area is cured for the period specified on the product data sheet before further coatings, waterproofing or decorative finishes are applied over it.
Tswanacrete is the authorised ABE Construction Chemicals distributor in Botswana. Confirm the correct product against the current data sheet for your specific application.
durarep FR is a polymer-modified, fibre-reinforced structural repair mortar used to reinstate spalled or broken-out concrete sections, built up to match the original profile. durarep FC is a one-component, polymer-modified cementitious blend used for a fair-faced finish or fairing concrete ahead of decorative coatings.
durarep FMC is a cement-based, non-shrink, high-strength fluid micro-concrete for larger repair volumes, applied by pouring or pumping, with a cured thermal coefficient matched to the surrounding concrete.
Exposed reinforcing steel is cleaned back to bright metal and primed with an anti-corrosion coating such as durarep ZR before any repair mortar is applied — skipping this is one of the most common causes of repeat spalling.
epidermix 344 and epidermix 345 are solvent-free structural epoxy adhesives used to bond new repair mortar to the existing prepared substrate, with epidermix 345 offering an extended open time. durabond GP is a modified acrylic emulsion bonding primer for cementitious repairs. aberep 710 is a two-part polymer-modified cement system for permanent, thin concrete repairs and floor patching up to 6mm.
Where the issue is an uneven or worn floor rather than structural spalling, ABE's abescreed range — SLCP, SLCP 25 and duraTop — are rapid-hardening, self-smoothing cement-based screeds for levelling floors ahead of carpet, tile, vinyl or resin finishes.
The right approach depends on a handful of project-specific factors.
Shallow patching, deep sectional repair, and larger pour-in volumes each call for a different product consistency and strength class.
Any repair involving exposed, corroded reinforcing steel needs anti-corrosion priming as a mandatory step, not an optional extra.
Structural damage affecting load-bearing capacity needs engineering assessment before a repair product is chosen; cosmetic surface defects have more flexibility in approach.
A repair that will be waterproofed, tiled, or coated afterward needs a finish and cure profile compatible with that next system — confirm this before starting.
Overhead repairs (soffits, beams) and vertical repairs need a non-sag product formulation different from a horizontal floor repair.
Repairs exposed to weather, chemicals, or heavy traffic afterward need a product rated for that ongoing exposure, not just the repair moment itself.
This is exactly the kind of decision our technical team can help with. Send us photos of the damage and rough dimensions, and we'll advise on the correct ABE repair system and sequence.
Most repeat failures trace back to a handful of recurring causes.
Patching over exposed, corroded reinforcing without priming — the corrosion continues to expand under the new patch and eventually cracks it back out.
Placing repair mortar directly onto prepared concrete without a bonding agent, so the patch sits on top of the substrate rather than becoming part of it.
Using a thin-section repair mortar in a deep pour, or a pourable micro-concrete where a trowelled mortar was needed.
Leaving weak, cracked or contaminated concrete at the repair edges instead of cutting back to sound material.
Coating, tiling or trafficking a repair before it has reached the cure period specified on the data sheet.
Repairing visible spalling without addressing an ongoing source of moisture or chloride ingress that will cause the same damage to recur nearby.
Concrete repair and waterproofing go hand in hand — a repaired section left unprotected against ongoing water ingress is likely to need repair again. See our Waterproofing Guide for how the two work together.
Spalling is usually caused by corroding reinforcing steel expanding inside the concrete and cracking it from within, though impact damage and repeated wetting and drying can also contribute.
No — this is one of the most common causes of repeat failure. Exposed, corroded steel must be cleaned back to bright metal and primed before any repair mortar is applied.
Cure times vary by product and section thickness and must be confirmed against the current ABE data sheet, which we supply with every order.
We supply product and technical guidance based on ABE's manufacturer data. For structural assessment or sign-off on significant damage, we can point you toward a suitably qualified structural engineer.
No. Fine surface cracking from shrinkage is common and often cosmetic, while cracking with rust staining, spalling or movement usually points to something more serious that should be assessed first.
Preparation, priming exposed steel, bonding and reinstatement.
Why waterproofing and concrete repair need to be planned together.
The full ABE range Tswanacrete supplies, and why buy through us.
Send us photos of the damage and rough dimensions, and we'll advise on the correct ABE repair system and sequence, with a written quotation in Botswana Pula.