Product collection

Admixtures for Semi-Dry Precast Concrete Products

UKCP precast admixtures improve the production of semi-dry concrete products such as blocks, bricks, paving flags, block paviours and roof tiles. The range includes CompaktAid and CompaktAid Plus compaction and processing aids and Xpress, an early strength activator for high GGBS mixes.

View all 3 products Precast Admixtures Datasheets

At a glance

Improved compaction and density
Better surface finish and colour
Reduced efflorescence
Higher early strength with GGBS

Precast Admixtures Products

There are 3 products in this collection. Select a product for full details, technical data and its downloadable datasheet.

Liquid Precast Admixtures

CompaktAid

UKCP CompaktAid is a precast block compaction and processing aid for dry and semi-dry concrete. It improves compaction, density and pigment dispersion, giving better colour intensity, a better surface finish and reduced efflorescence in blocks, paving flags and block paviours.

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Liquid Precast Admixtures

CompaktAid Plus

UKCP CompaktAid Plus is a high performance semi-dry precast compaction and processing aid. It combines improved compaction with better cement dispersion to help improve early strengths, and offers binder reduction and reduced efflorescence in blocks, paving and roof tiles.

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Powder Precast Admixtures

Xpress

Xpress is an early strength activator for precast concrete based on CEMI and GGBS binder systems. It boosts early age strengths where at least 50% GGBS is used, improving handling and reducing breakages in semi-dry units such as blocks and bricks.

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Need the technical data?

Download the datasheets for all 3 precast admixture products, or request a sample to try on your next job.

Datasheets Request a Sample

Semi-dry concrete products are made on high speed machines where compaction, early strength and appearance decide how many good units come off the line. UKCP precast admixtures target each of those.

What is in the precast admixtures range?

CompaktAid: compaction and processing aid for blocks, paving flags and block paviours.
CompaktAid Plus: high performance compaction and processing aid, including roof tiles.
Xpress: early strength activator for CEM I and GGBS blended precast concrete.

For surface protection of finished blocks and bricks, see BlokSeal. For mould release, see our release agents. For accelerators and superplasticisers used in structural precast, see our concrete admixtures.

Talk to our technical support team about trials on your line, or request a sample.

Technical Datasheets

Download the datasheet for each product in this collection.

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Precast Admixtures FAQs

Answers to common questions about this collection. For advice on a specific mix or project, contact our technical team.

What does a compaction aid do in semi-dry concrete?

A compaction aid helps a semi-dry mix compact more fully in the machine, which increases density and reduces porosity. CompaktAid and CompaktAid Plus also improve processing, surface finish and colour consistency and help reduce efflorescence. Improved compaction also reduces machine stress and parts wear.

What is the difference between CompaktAid and CompaktAid Plus?

Both are liquid compaction and processing aids for semi-dry concrete. CompaktAid Plus is the high performance version, which also improves cement dispersion to help early strengths and lists binder reduction among its benefits. Its typical dosage range is 0.30% to 2% by weight of cement, against 0.20% to 0.60% for CompaktAid.

How can I stop GGBS blocks breaking at palletisation?

High GGBS contents in semi-dry, low binder mixes can leave units too weak to handle after curing. Xpress activates the reaction between CEM I and GGBS for higher early age strengths, improved handling and fewer breakages, with a minimum GGBS content of 50%.

How do I find the right dosage?

Dosage depends on the mix design, process, aggregate type and consistency required. The correct dose should be determined by trials. Contact our technical support team for advice.