Admixtures
Xypex Concrete Admixtures
Xypex Concrete Admixtures are powdered form products, consist of Portland cement and active proprietary chemicals, which are added to the concrete mix at time of batching.
Research studies have confirmed that the Xypex Admix C-Series modifies the microstructure of the concrete and enhance the durability performance of the concrete by blocking the pores and healing the cracks up to 0.4 mm. Case studies have revealed that Xypex Admix C-Series is able to significantly extend the service life of the reinforced concrete structures exposed to aggressive environments.
Moreover, Xypex products improves mechanical properties of the concrete as well.
All “crystalline additives” available in the market might appear similar to each other in the bag, however there is significant variation in terms of chemical composition under XRF (X-ray Fluorescence Analysis) and most importantly performance compliance to Australian Standard AS1478.1 – 2000, Chemical Admixtures for Concrete, for Special Purpose Normal-Setting (Type SN) Admixture.
Sorptivity is not the best test for durability. It is only part of a number of tests available for durability assessment. Project objectives and conditions would determine the suitable durability test in the service life assessment. For example, a chloride diffusion test would be more suitable for a marine project where chloride ingress protection is required.
Other durability testing methods include water permeability and accelerated chloride diffusion tests.
Click here for downloadable shortform specification, which outlines suitable durability tests for “crystalline additive products”.
Xypex does not give off an odour or provide any WHS issues. Xypex products also comply with Australian Standards AS4020:2005 Testing of Products for use in contact with Drinking Water. Click here for downloadable compliance certificates.
Xypex Crystalline Admixture C-Series complies with Australian Standard AS 1478.1:2000, Chemical Admixture for Concrete for Special Purpose Normal-Setting (Type SN) Admixture. Click here to download compliance certificate.
Xypex Admix products comply with Australian Standards AS/NZS 4020:2005 Products for use in contact with Drinking Water. Click here to download compliance certificates.
Xypex Admix has been tested and proven it is compatible with concrete mix design with inclusion of Supplementary Cementitious Materials (Fly Ash, GGBS, Silica Fume). Information on properties of concrete modified with Xypex Admix is available upon request or please visit Xypex Testing for details.
Penetrability-reducing admixtures form a new class of chemical admixtures that can reduce the rate of transmission of moisture either in a liquid or vapour form through concrete. It is the moisture transportation that plays an important role as a vehicle carrying chlorides and other aggressive ions into concrete through the pore system.
Several types of penetrability-reducing admixtures are commercially available. Some of these are classified as hydrophobic admixtures due to the presence of long-chained fatty acids or vegetable oils. These tend to have more effect on absorption than permeability; therefore they are not suitable for concrete structures subjected to hydrostatic pressure.
Xypex Admix C-Series is classified as a microstructure modifier which reduces concrete permeability through crystallisation activity in concrete pores. It has the ability to greatly reduce water penetration and also impart good resistance to chemical attack in concrete.
Xypex Admix C-Series is a permeability-reducing admixture characterised by crystallization reactivity and is an inorganic admixture. The active ingredients in Xypex react with a broad range of hydration by-products which include various metal oxides and salts, unhydrated and partially hydrated cement particulates as well as calcium hydroxide, regardless of the Portland or blended cement types. The reactive products of Xypex Admix are in mineral crystal form and grow in the residual voids (pores and cracks) in concrete, with a unique ability to self-heal hairline cracks up to 0.4mm.