1. Fly ash used in concrete production
TAURON Wytwarzanie Spółka Akcyjna - Oddział Jaworzno III Power Plant has had the EC Certificate of Conformity for the construction product Fly ash used in concrete production. This certificate means that fly ash used in concrete production became a rightful construction product affixed with CE marking and lost its waste status.
Fly ash used in concrete production manufacture in PKE SA Jaworzno III Power Plant is successful utilized in concrete industry to produce ready-mixed concrete and in the cement industry used as a mineral additive in the cement production.
In order to obtain the EC Certificate of Conformity for the fly ash used in concrete production a quality system compliant with the requirements of the below given harmonized norms PN – EN 450 – 1. Fly ash for concrete. Part 1: Definitions, specification and conformity criteria and PN – EN 450 – 2. Fly ash for concrete. Part 2: Conformity assessment had to be implemented.
2. Production Quality System of Fly Ash used in Concrete Production
The Building Research Institute (Instytut Techniki Budowlanej – ITB) in Warsaw, accredited in PCA for certifying products and management systems accreditation no AC 020 and AC 072), was selected as the certifying authority. ITB Warsaw is authorized by the Ministry of Infrastructure to carry out tasks regarding conformity assessment pursuant to the Directive 89/106/EEC. This authorization is an official confirmation of ITB competences with respect to tasks to be carried out by an entity independent of the manufacturer regarding construction products. Decision on the ITB authorization and the authorization scope was notified to the European Commission and other European Union Member States. Thus ITB became a European notified body entered to the European Commission database (NANDO CPD) under the number 1488.
Supervision of the certification is also carried out by the Building Research Institute. An annual audit executed by the Institute employees is one of the supervision process elements. The audit objective is to confirm the compliance of the functioning Production Quality System of Fly Ash with the requirements of norm PN – EN 450 – 1. Fly ash for concrete.
PKE SA Jaworzno III Power Plant Chemical Analyses Department executes laboratory tests of fly ash samples chemical and physical parameters for the needs of the Production Quality System of Fly Ash. Quality and reliability of the tests executed in the laboratory are confirmed by the accreditation certificate no AB 688 issued by the Polish Center for Accreditation which is the only entity in Poland authorized to recognize the competences of testing and calibrating laboratories. Part of the tests is also executed in Opole Institute of Glass, Ceramics, Refractory and Construction Materials which is an accredited in PCA under number AB 373.
Tests results are directly submitted to the Production Quality System of Fly Ash Manager who is in charge of ongoing quality control of the manufactured product and the conformity assessment of the fly ash chemical and physical parameters with regard to the requirements stipulated in the reference document.
ITB Warsaw carries out periodic assessment of the product test results regarding the requirements stipulated in the reference document as part of the certification supervision process.
The quality system implemented by PKE SA Jaworzno III Power Plant shows full compliance with the norm PN – EN 450 – 1 and guarantees high quality of the manufactured product.
3. Product description. Fly ash as an additive to cement and concrete
Until recently fly ash was a troublesome waste of electrical energy generation. Nowadays it is no longer perceived as a cheap cement substitute, filler or an additive but as a valuable component of the concrete mixture which enhances the mixture and the concrete in many ways. Fly ash is also a crucial mineral additive in the production of cement. Its vast application range in the cement industry result mainly from the fly ash properties such as fineness, chemical composition similar to natural materials as well as pozzolanic properties i.e. capability of binding calcium hydroxide in the presence of moisture. Application of fly ash as the mineral additive for the production of cement is regulated in norm PN – EN 197 – 1. Cement. Part 1. Composition, requirements and conformity criteria concerning cement for wide use.
Cements with the addition of fly ash have better properties compared to the Portland cement, e.g.:
- longer binding time,
- good workability of the concrete mix,
- low heat of hydration (minimizing the occurrence of too big stress in mass constructions),
- significant durability increase throughout a longer period of time,
- increased corrosion resistance.
Apart from using fly ash as cement component, fly ash is also used as a substitute of cement in the production of concrete. Addition of the fly ash in concrete has positive influence on:
- increase of the concrete durability over a longer period of time,
- decrease of the thermal effects of the mix components hydration,
- increase of the concrete resistance to chemical corrosion,
- increased concrete tightness,
- improvement of the concrete workability.
Production of cements and concrete with the addition of fly ash also has positive impact on the natural environment protection as it:
- decreases the electrical energy consumption during cement production,
- decreases CO2 emission during cement production,
- decreases the consumption of raw materials.
One should emphasize that from the moment the harmonized norm PN - EN 450 was implemented in 2005 only fly ash with EC Certificate of Conformity can be used in construction industry. Thanks to the EC Certificate of Conformity for the fly ash for concrete, PKE SA Jaworzno III Power Plant commenced selling a new, high quality product and significantly reduced the volume of furnace wastes produced.
English
Polski
