Mixed to resist.The new generation of SITREN® shrinkage reducing agents.

Additives and active ingrediants for the concrete admixture industry

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Our management systems for the concrete admixture industry

Shrinkage describes a volume reduction of cementitious based products due to a change in the water content.

In addition to environmental infl uences and internal dehy-dration, chemical/mineral reactions also play an important role. This volume reduction can aff ect both the shape of the concrete element as well as its bearing points. Prevention of the free shrinkage results in the build-up of internal forces and tensions, which can lead to deformations and crack for-mation.

Application areas:

� In-situ und ready-mixed concrete � Prefabricated concrete � Concrete products (paver and bricks) � Concrete screeds � Special concrete (e.g. HPC und UHPC) � Architectural concrete � Reinforced concrete � Self-compacting concrete

Infl uence factors of shrinkage

The most important factors infl uencing shrinkage are low humidity, wind, solar radiation and unfavourable temperatures as well as the respective concrete compo-sitions and component dimensions.

The fi nal properties of concrete structures are largely determined by controlling the water content and errors made at the beginning cannot be corrected later. The loss of moisture from fresh concrete results in a reduction in volume and can lead to shrinkage cracking which can occure within a few hours.

A lack of water may prevent the cement from fully hydrating which may result in loss of compressive strength, reduced frost resistance and susceptibility to chemical attack which can all have adverse eff ects on its durability.

Curing Management Shrinkage reducing agents

Our fi ve unique management systems always provide our customers with a targeted and eff ective product solution for the respective challenge.

Process and Performance Additives for the concrete admixture industry

Air-entraining agent

Defoamers

AirVoid Management

Hydrophobingagent

ProtectionManagement

Shrinkage reducing admixtures

CuringManagement

Wetting agentDispersantDefoamer

FormulationManagement

Release agents

ReleaseManagement

SITREN®, SITREN AirVoid®, TEGOSIVIN® and TEGO® Antifoam

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Our SITREN® shrinkage reducing agents, devel-oped in close cooperation with the admixture industry, stand out ecologically as well as techni-cally. The reduction in the capillary pressure and the stress in the pore structure, results in markedly reduced shrinkage and thus in the prevention of crack formation. The cement setting and the con-crete early strength are not aff ected. In combina-tion with an optimized water content, our new generation of shrinkage reducing agents also ensure improved durability.

Minimize shrinkage – Increase durabilityTechnical and aesthetical demands for a concrete are higher than ever before.

Lack of shrinkage control has a strong impact on the use and durability of the

building materials.

Evonik recognizes that sustainability is of utmost importance for all our futures. As a result, our product development focuses on high-performance products that are friendly to our environment.

With this in mind, Evonik has developed a new generation of SITREN® shrinkage reducing agents. Thanks to their extre-mely low VOC content, SITREN® shrinkage reducing agents are able to meet the most stringent eco label requirements such as EMICODE EC1PLUS – and without any dosage restrictions.

The setting characteristics of cement based building materials have a considerable infl uence on its fi nal properties. The hardening of mineral building materials results from a large number of complex processes. It is especially important to avoid cracking and minimize shrinkage.

Our new generation of shrinkage reducing agents frequently out-perform other commercially available products. They can reduce drying shrinkage as well as plastic shrinkage, and enhance the workability of the cementitious system whilst having no eff ect on the setting process. A signifi cantly reduced number of capillary pores with simultaneously increased micro pore content leads to lower porosity and thus, to a more dense microstructure.

Keeping the shape!Ensuring stability with our shrinkage reducing agents.

SHRINKAGE REDUCING AGENTS – AT A GLANCE

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Product overview

PRODUCT CHEMICAL CHARACTERIZATION

ACTIVE INGREDIENT CONTENT [%]

RECOMMENDED DOSAGE* [%]

SITREN® SRA L 210 Modified polyether 100 0.5 - 2.5

* based on cement

Appropiate measurements of plastic shrinkage with shrinkage channels confi rmed the high performance of SITREN® SRA L 210.

Cracking of concrete surface without shrinkage reducing agent Crack prevention in concrete by using SITREN® SRA L 210

The use of SITREN® has almost no impact on early strength or set times compared to neopentyl glycol.

Flexural strength / compressive strength aft er 1 day

Setting by Vicat

SITREN® SRA L 210 not only signifi cantly reduces drying shrinkage, also known as capillary shrinkage, but also plastic shrinkage within the fi rst 24 hours.

Formulation Cement (CEM I 42.5 N): 375 kg/m3

Water (w/c: 0.45): 169 kg/m3

Aggregates (0–2 mm): 570 kg/m3

Aggregates (2–8 mm): 679 kg/m3

Aggregates (8–16 mm): 587 kg/m3

SITREN® SRA L 210: 7.5 kg/m3

PCE plasticizer: 1.9 kg/m3

SITREN® SRA L 210 REDUCES DRYING SHRINKAGE

Shrinkage over a period of 90 days

SIGNIFICANT REDUCTION OF PLASTIC SHRINKAGE BY USING SITREN® SRA L 210SITREN® SRA L 210 HAS ALMOST NO IMPACT ON THE SETTING BEHAVIOUR

Shrinkage over a period of 24 hours

Shrinkage refers to the volume reduction of cementitious products over time. The water balance in these systems plays a central role, since the shrinkage processes or the subsequent drying of these materials are promoted by the chemical reaction of the binders with water.

There are basically three types of shrinkage:

1. Chemical or autogenous shrinkage – through water removal in the chemical reaction between water and cement.2. Plastic shrinkage – resulting from the evaporation of the excess water as long as the cement-based building material

can still be processed.3. Long-term shrinkage or drying shrinkage – as a result of the drying out of cement based building material over time.

Our novel shrinkage reducing admixtures are based on the latest raw material technologies and signifi cantly infl u-ence the process of plastic and drying shrinkage. SITREN® SRA L 210 is a liquid shrinkage reducing agent based on modifi ed polyethers to prevent cracking of cement based building materials.

SITREN® Shrinkage reducing agents

25

20

15

10

5

0Compressive strength Flexural strength

Stre

ngth

[N/m

m2 ]

500

400

300

200

100

0Initial Final

Reference

NPG (Neopentyl glycol)*

SITREN® SRA L 210*

* Dosage: 2 % based on cement Formulation: Standard mortar acc. to DIN EN 196

Set t

ime

[min

.]

Additional shrinkage reducing agents and further information are available in our product overview or on request.

0.300

0.200

0.150

0.050

0.000

0 15

Concrete withSITREN® SRA L 210

Reference0.100

0.250

5 10 20

Hours [h]

Shrin

kage

[mm

/m]

Concrete withSITREN® SRA L 210

Reference

0.6

0.4

0.3

0.1

0

0 30 60 90

0.2

0.5

10 20 40 50 70 80

Days [d]

Shrin

kage

[mm

/m]

03/2

017

Inv.

-Nr.:

19-

17

Asia | Pacifi c

EVONIK DEGUSSA SPECIALTY CHEMICALS CO, LTD.55, Chundong RoadXinzhuang Industry ParkShanghai, 201108PR ChinaPHONE +86 21 6119-1125 FAX +86 21 6119-1406

The Americas

EVONIK CORPORATION 7801 Whitepine RoadP.O. Box 34628 Richmond, VA 23234 USAPHONE +1 804 727-0700 FAX +1 804 727-0855

Europe | Middle East | Africa

EVONIK NUTRITION & CARE GMBHGoldschmidtstraße 10045127 EssenGermanyPHONE +49 201 173-2665FAX +49 201 173-1990www.evonik.com

This information and any recom-mendations, technical or otherwise, are presented in good faith and believed to be correct as of the date prepared. Recipients of this infor-mation and recommendations must make their own determination as to its suitability for their purposes. In no event shall Evonik assume liability for damages or losses of any kind or nature that result from the use of or reliance upon this information and recommendations. EVONIK EXPRESSLY DISCLAIMS ANY REPRESENTATIONS AND WARRANTIES OF ANY KIND, WHETHER EXPRESS OR IMPLIED, AS TO THE ACCU-RACY, COMPLETENESS,

NON-INFRINGEMENT, MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR PURPOSE (EVEN IF EVONIK IS AWARE OF SUCH PURPOSE) WITH RESPECT TO ANY INFORMATION AND RECOM-MENDATIONS PROVIDED. Reference to any trade names used by other companies is neither a recommendation nor an endorse-ment of the corresponding product, and does not imply that similar products could not be used. Evonik reserves the right to make any changes to the information and/or recommendations at any time, without prior or subsequent notice.www.evonik.com/

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