Superplasticizers in Concrete and Construction Chemicals

Plasticizers in Concrete and Construction Chemicals Before discussing the properties of our plasticizers, I would like to first define them in general terms and provide some historical background. Plasticizers are used to ensure that mortar manufactured without reducing the required amount of cement or compromising strength becomes fluid and easily workable, and to achieve high-strength concrete and construction chemicals by lowering the water/cement ratio. When savings are made by reducing both water and cement quantities while keeping the water/cement ratio constant, plasticizers are employed to maintain workability at its initial level. Plasticizers are organic substances that reduce the surface tension of water through their porous chemical structure that dissolves in water, and they become effective by entraining air into the product being used and preventing cement agglomeration.

Why Should We Use Them?

• They reduce the surface tension of water and increase wetting power, • They convert cement particles into a hydrophilic state, • They prevent agglomeration (flocculation) of cement particles and provide homogeneous dispersion. In general terms, superplasticizers are a relatively new admixture group, but the dispersing capabilities of chemicals containing them have been known since the 1930s. These admixtures are also known as superplasticizers or high-range water-reducing admixtures and can be used at significantly higher doses than ordinary water-reducing admixtures without negative side effects such as greatly delaying hardening. Therefore, in concretes with normal workability (~30%), the volume of mixing water can be reduced much further, or alternatively, 'self-consolidating concrete' can be obtained without adding excess water to the mixture. Sulfonated melamine-formaldehyde condensates; these synthetic polymers, developed in Germany and commercially introduced in 1964, have a structural formula as shown below and each repeating unit contains a sulfonate group. The degree of condensation (n) typically ranges from 50-60 and gives a molecular weight on the order of 12,000-15,000. The sodium salt is highly soluble and is preferred for use as an admixture. Plasticizers are linear polymers containing sulfonic acid groups bonded at periodic intervals to the polymer structure. These types of products can be classified into four groups: • Sulfonated melamine-formaldehyde condensates (SMF), • Sulfonated naphthalene-formaldehyde condensates (SNF), • Modified lignosulfonates (MLS), • Polycarboxylate derivatives.   In construction chemicals, leveraging our established position in both domestic and export markets, Günkem offers our customers Reamin MF 100 Superplasticizer and Reomax 3904 Hyperplasticizer products in this category. In this article, we will primarily provide information about our superplasticizer REAMİN MF 100 - sulfonated melamine formaldehyde and our hyperplasticizer REOMAX 3904 P, which is polycarboxylate-based, and their applications in the sector, targeted at users and product developers. Although superplasticizers have traditionally been referred to primarily as concrete admixtures, their use in dry mortar product groups has become increasingly widespread in recent times, along with growing application requirements and final product quality expectations. According to product groups used in the construction chemicals sector, our REAMİN MF 100 product benefits the workability, spread, strength and water-reduction properties of related dry mortar products, improving both the application quality and the hardened mortar quality of the products. In summary, dry mortar manufacturers and product developers can benefit from practical application knowledge according to the related product groups mentioned below.

Joint Fillers

In joint filler product groups, fillers such as calcite, dolomite and limestone below 100 microns can increase the water requirement of the product and adversely affect application. Here, manufacturers and product developers can improve both the workability and application properties of the product as well as final strength values by using Reamin MF 100 at a rate of 0.10-0.20%.

Thermal Insulation and Coating Mortars

Under normal conditions, when high-viscosity hpmc and mhec cellulose are used, application qualities of thermal insulation mortars can be adversely affected. With the addition of 0.05-0.10% REAMİN MF 100, the application properties of thermal insulation mortars are improved.

Tile Adhesives

Particularly in ceramic tile adhesives in the C1FT class, when high amounts of cement and at the same time aluminate cement are used, the product's water/cement ratio may increase. By using REAMİN MF 100 at approximately 0.10%, the water amount can be reduced and the drop in bond strength of tile adhesives can be prevented.

Surface Hardeners

These products are applied to concrete that is about to cure in order to add color, increase surface wear resistance and strength. When REAMİN MF 100 is used, homogeneous distribution of the surface hardener product on the concrete surface is ensured, preventing color fluctuations.

Cement-Based Waterproofing Products - 2K (Powder and Acrylic)

2K waterproofing products are generally applied with a brush. REAMİN MF 100 at a rate of 0.10-0.20% improves the workability and brush application properties of the product. This also contributes to the application of the product at the same thickness.

Self-Leveling Floor Screeds

In grout and leveling screeds, REAMİN MF 100 can be used in the range of approximately 0.60-0.80%. Reamin MF 100 provides better spread characteristics compared to market equivalents and improves early strength properties, thereby allowing self-leveling floor screeds to be put into use in a shorter time after application.   Our product in the hyperplasticizer group, REOMAX PC 3904, is a polycarboxylate-based hyperplasticizer in powder form that reduces mixing water at high rates and imparts high fluidity, used at much lower rates compared to superplasticizers. Recently in the market, polycarboxylate-based products are frequently used in dry mortar product groups in addition to serving as concrete admixtures. Offering advantages in terms of dosage rate (0.20-0.30%), this product of ours is competitively positioned in the market in terms of quality/cost compared to competitors. REOMAX PC 3904 reduces the water/cement ratio by approximately 30% and provides advantages in terms of early strength, workability and spread values. Based on our customers' requirements, our superplasticizer REAMİN MF 100 and hyperplasticizer REOMAX 3904 PC products allow us as Günkem to provide competitive (quality/price/fast service) technical solutions, contributing to the increased use of related products particularly in the dry mortar sector, and will continue to do so through monitoring developing technology. Yusuf Baydar Technical Sales Manager Günkem