patching up concrete ?

[steveo3002]

got some odds n ends around the garden where the concrete has chipped away over time, ive tried smearing a bit on but it never sticks for long

is there any tricks of the trade how to prepare and patch up such jobs , noting structural just for appearance saje

 

[Dcal]

Mix up SBR with cement to a thick paste, paint it on to the damaged concrete and then, before it's cured, apply sand and cement or concrete to finish the repair.

 

[nickk]

If it’s edges breaking loose,I drill several holes wherever it’s in sound condition,then hammer or screw in some steel studs,making sure I can get 2-3” cover of additional concrete over it to ensure it’s bound to the original.

 

[brightspark]

prime with sbr then ad a bit of it to the sand and cement and it will stick like sh,it to a blanket

 

[Tom O]

What’s SBR?

 

[Onoff]

What’s SBR?

Like PVA on steroids. It's waterproof whereas normal PVA isn't. SBR is a bit like tile primer.

 

[Onoff]

You can always drill and resin fix stainless steel studs in before adding your SBR mix. Be warned though, SBR laden mixes set real quick.

 

[Onoff]

"P.R. EPOXY - SBR POLYMER SYSTEM

TECHNICAL DATA SHEET

USES.
P.R. Epoxy - SBR Polymer System is used for screeds, floor repairs, waterproof renders, waterproof fine concretes and bonding.

DESCRIPTION
P.R. Epoxy - SBR Polymer System has been formulated to enhance the physical and chemical properties of cement mortars and concretes. It is compatible with most forms of cement, sands and aggregates. Together with the cement, it forms a powerful adhesive to bond the aggregates together, producing a tougher, waterproof and more impact and abrasion resistant floor, repair mix, render or bonding primer.

PROPERTIES
The properties of the cured mix will vary depending on the type of cement, sand and aggregates used.

COMPRESSION
AGE. N/mm²
1 day 14 – 18
28 days 40 – 50
(Strength is dependent on mix design)

PREPARATION
Surfaces to which P.R. Epoxy - SBR Polymer System mixes are to be applied must be clean, strong and free from oil, grease and with a rough profile. Best preparation is with a scabbler or power washer. If metal surfaces area to be covered they must be rust free and wire brushed or grit blasted. Cement based substrates must be damped with clean water and excess water removed. A primer coat of 1:1 P.R. Epoxy - SBR Polymer System/cement is brush applied to the prepared surface. Refer to relevant standards and codes of practice.

MIXING & APPLICATION
Hand mix or use a forced action mixer. The components of the selected mix are measured by weight or volume and dry mixed. The P.R. Epoxy - SBR Polymer System and water is added to give the desired consistency. In an efficient mechanical mixer, mixing should continue for 2-3 minutes. When hand mixing, mix the cement, aggregate and sand dry then add sufficient of the P.R. Epoxy - SBR Polymer System/water until a homogeneous consistency is achieved.
The mixed mortar is applied to the prepared and primed surface whilst the primer is still wet/tacky, using conventional screeding, rendering and concreting techniques. Apply as required on to wet or tacky primer, compact well and finish. If the primer dries, crosshatch scratch and reapply. If necessary apply mortar in multiple layers to achieve total thickness, priming between layers with P.R. Epoxy - SBR Polymer System :cement primer.

STORAGE
P.R. Epoxy - SBR Polymer System must be stored unopened in dry warehouse conditions between +5°C and 25°C and out of direct heat and sunlight. In these conditions P.R. Epoxy - SBR Polymer System should have a shelf life of approximately 12 months.

PACKAGING
P.R. Epoxy - SBR Polymer System is available in 5, 25 and 240.0litre containers.

HEALTH & SAFETY
There are no emissions of noxious or offensive fumes, P.R. Epoxy - SBR Polymer System is alkaline when mixed with cement and sand; do not allow prolonged contact with skin. Health & Safety information is available.

OTHER INFORMATION
Mix Design’s

1. Floor Screeding and Screed Repair (min. 6mm)
by weight by volume
50kg cement 1 pbv
150kg medium sand 2.5 pbv
10 litres SBR (1:1 SBR:water
9 litres water* (add to consistency
Yield approx 0.1m³

2. Heavy duty floor toppings (min. 12mm)
by weight by volume
50kg cement 1 pbv
75kg medium sand 1.25 pbv
75kg 6-3mm grano chips 1.25 pbv
10 litres SBR (1:1 SBR:water
9 litres water* (add to consistency
Yield approx 0.11m³

3. Waterproof Renders (min.6mm)
by weight by volume
50kg cement 1 pbv
125kg medium sand 2 pbv
10 litres SBR (1:1 SBR:water
9 litres water* (add to consistency
Yield approx 0.1m³

4. Water Resistant Concrete (min.25mm)
by weight by volume
50kg cement 1 pbv cement
100kg medium sand 1.5 pbv
100kg 10-5mm pea shingle 1.5 pbv
5 litres SBR (1:3 SBR:water
13 litres water* (add to consistency
Yield approx 0.14m³

5. Bonding Screeds, Plaster, New Concrete to Old
by weight by volume
1kg cement 1 pbv cement
1 litre SBR 1 pbv SBR
Yield approx 3-4m² per litre

6. Floating Screeds (min. 38mm)
by weight by volume
50kg cement 1 pbv
150kg medium sand 2.5 pbv
4.5litres SBR (1:3 SBR:water
13.5 litres water* (add to consistency
Yield approx 0.1m³

• * = add to working consistency.
• All sands must be medium grade sharp.
• Aggregates must be clean, well graded and not “to dust”.
All P.R. Epoxy Systems products’ are manufactured to a high standard of quality. Whilst we aim to ensure that any advice, information or recommendations given are reliable and correct, the Company cannot accept any liability directly or indirectly arising from the use of its products, as we have no direct or continuous control over where or how its products are applied. No undertaking can be given against infringement of any patented processes."

 

[Onoff]

Typical SBR data sheet:

 

[Pond frog]

I did some repairs a few weeks ago using the method described by Dcal works very well. Fortunately I had some SBR in the shed that had been left behind when I had builders in as it can be a bit pricey

 

[Pete.]

For tiny cosmetic repairs I use Ardex a46. You can buy it in a bucket from Travis. It mixes into a stiff smooth mix which you trowel on, cures quite quickly and can be sanded.

 

[brightspark]

I did some repairs a few weeks ago using the method described by Dcal works very well. Fortunately I had some SBR in the shed that had been left behind when I had builders in as it can be a bit pricey

about 18 quid a gallon

 

[bricol]

I tried the sbr/cement as per instructions on the container earlier this year for the first time - brushed it on, then applied cement mixed with it as a waterproofing agent to form a fillet of cement inside a prefab garage. Applied some as a test to non treated floor.

Impressive night and day difference to adhesion!

 

[brightspark]

I tried the sbr/cement as per instructions on the container earlier this year for the first time - brushed it on, then applied cement mixed with it as a waterproofing agent to form a fillet of cement inside a prefab garage. Applied some as a test to non treated floor.

Impressive night and day difference to adhesion!

yep on damp proofing a wall or floor. you 1st make a paste up of sbr and just cement and paint on thats the primer coat then you make a paste up of sbr and tanking slurry and paint that on then give it a second coat job done plaster or clad after

 

[Onoff]

Tbh I reckon you could use tile primer if you had some.

 

[DAPPH]

For tiny cosmetic repairs I use Ardex a46. You can buy it in a bucket from Travis. It mixes into a stiff smooth mix which you trowel on, cures quite quickly and can be sanded.

Sounds good for repairing reinforced cast concrete window cills ,, I suppose you have to acid etch the steel rebar to clean it & neutralize it with washing soda water before applying . Any thought or other points to consider as I'll be seeking to repair three cast window cills in the not too far distant future .

 

[Pete.]

Sounds good for repairing reinforced cast concrete window cills ,, I suppose you have to acid etch the steel rebar to clean it & neutralize it with washing soda water before applying . Any thought or other points to consider as I'll be seeking to repair three cast window cills in the not too far distant future .

That's exactly what I used it for.

Most rebar you see put in for concreting is rusty I would not bother with any sort of rust inhibitor once the concrete is cured there will be no moisture or oxygen to carry on rusting.

 

[steveo3002]

thanks all , i hadnt got notifcations for some reason

will have a look for a small tin of this sbr

 

[brightspark]

thanks all , i hadnt got notifcations for some reason

will have a look for a small tin of this sbr

comes in smaller buckets at wickes https://www.wickes.co.uk/KA-Bond-SB...MI47aRgaT_iAMVn5JQBh36TDvDEAQYAiABEgILNvD_BwE

 

[Onoff]

once the concrete is cured there will be no moisture or oxygen to carry on rusting.

Ooh! Cat / pigeons...

As I understand it then traditional, new concrete starts of as an alkaline medium which is great for protecting the steel. Over time, I think it's CO2 seeps in and turns it acid. Literally it carbonates the concrete.

There was a product called Ferrogard, used on the old concrete art deco places, brought out that prevents / halts this. Somewhere I have a great press cutting on it. I think Sika bought them out maybe?

Fascinating stuff if you haven't got a life like me...

Sika solution for Hoover Building - The Structural Concrete Alliance

Sika supplied the long-term concrete repair and protection solution to the Hoover Building, a Grade II-listed Art Deco building built in the 1920s.

www.structuralconcretealliance.com