Influence of the active additives on the structure and properties of expanded-clay lightweight concrete ; Aktyviųjų priedų poveikis keramzitbetonio struktūrai ir savybėms
24 pages
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Influence of the active additives on the structure and properties of expanded-clay lightweight concrete ; Aktyviųjų priedų poveikis keramzitbetonio struktūrai ir savybėms

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VILNIUS GEDIMINAS TECHNICAL UNIVERSITY Marija VAIČIENĖ INFLUENCE OF THE ACTIVE ADDITIVES ON THE STRUCTURE AND PROPERTIES OF EXPANDED-CLAY LIGHTWEIGHT CONCRETE SUMMARY OF DOCTORAL DISSERTATION TECHNOLOGICAL SCIENCES, CIVIL ENGINEERING (02T) Vilnius 2011 Doctoral dissertation was prepared at Vilnius Gediminas Technical University in 2006–2011. Scientific Supervisor Prof Dr Habil Romualdas MAČIULAITIS (Vilnius Gediminas Technical University, Technological Sciences, Civil Engineering – 02T). Consultant Assoc Prof Dr Ramun ŽURAUSKIE (Vilnius Gediminas Technical University, Technological Sciences, Civil Engineering – 02T). The dissertation is being defended at the Council of Scientific Field of Civil Engineering at Vilnius Gediminas Technical University: Chairman Prof Dr Povilas VAIIŪAS (Vilnius Gediminas Technical University, Technological Sciences, Civil Engineering – 02T). Members: Prof Dr Habil Juozas ATKOČIŪAS (Vilnius Gediminas Technical University, Technological Sciences, Civil Engineering – 02T), Assoc Prof Dr Darius BAČISKAS (Vilnius Gediminas Technical University, Technological Sciences, Civil Engineering – 02T), Dr Mindaugas DAUKŠYS (Kaunas University of Technology, Technological Sciences, Civil Engineering – 02T), Prof Dr Habil Vytautas STAKEVIČIUS (Kaunas University of Technology, Technological Sciences, Civil Engineering – 02T).

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Publié le 01 janvier 2012
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VILNIUS GEDIMINAS TECHNICAL UNIVERSITY
Marija VAIČIENĖ
INFLUENCE OF THE ACTIVE ADDITIVES ON THE STRUCTURE AND PROPERTIES OF EXPANDED-CLAY LIGHTWEIGHT CONCRETE
SUMMARY OF DOCTORAL DISSERTATION TECHNOLOGICAL SCIENCES, CIVIL ENGINEERING (02T)    
Vilnius  
 
 2011
 
Doctoral dissertation was prepared at Vilnius Gediminas Technical University in 2006–2011.  Scientific Supervisor Prof Dr Habil Romualdas MAČIULAITIS Gediminas (Vilnius Technical University, Technological Sciences, Civil Engineering – 02T). Consultant Assoc Prof Dr Ramun ŽURAUSKIE(Vilnius Gediminas Technical University, Technological Sciences, Civil Engineering – 02T). The dissertation is being defended at the Council of Scientific Field of Civil Engineering at Vilnius Gediminas Technical University: Chairman Prof Dr Povilas VAIIŪAS(Vilnius Gediminas Technical University, Technological Sciences, Civil Engineering – 02T). Members: Prof Dr Habil Juozas ATKOČIŪAS (Vilnius Gediminas Technical University, Technological Sciences, Civil Engineering – 02T), Assoc Prof Dr Darius BAČISKAS(Vilnius Gediminas Technical University, Technological Sciences, Civil Engineering – 02T), Dr Mindaugas DAUKŠYS(Kaunas University of Technology, Technological Sciences, Civil Engineering – 02T), Prof Dr Habil Vytautas STAKEVIČIUS(Kaunas University of Technology, Technological Sciences, Civil Engineering – 02T). Opponents: Prof Dr Habil Stasys BOČKUS(Kaunas University of Technology, Technological Sciences, Materials Engineering – 08T), Assoc Prof Dr Gintautas SKRIPKIŪAS(Vilnius Gediminas Technical University, Technological Sciences, Civil Engineering – 02T). The dissertation will be defended at the public meeting of the Council of Scientific Field of Civil Engineering in the Senate Hall of Vilnius Gediminas Technical University at 1 p. m. on 6 January 2012. Address: Saultekio al. 11, LT-10223 Vilnius, Lithuania. Tel.: +370 5 274 4952, +370 5 274 4956; fax +370 5 270 0112; e-mail: doktor@vgtu.lt The summary of the doctoral dissertation was distributed on 5 December 2011. A copy of the doctoral dissertation is available for review at the Library of Vilnius Gediminas Technical University (Saultekio al. 14, LT-10223 Vilnius, Lithuania).  © Marija Vaičien, 2011
 
 
VILNIAUS GEDIMINO TECHNIKOS UNIVERSITETAS
Marija VAIČIENĖ
AKTYVIŲJŲ PRIEDŲ POVEIKIS KERAMZITBETONIO STRUKTŪRAI IR SAVYBĖMS
DAKTARO DISERTACIJOS SANTRAUKA
TECHNOLOGIJOS MOKSLAI, STATYBOS INŽINERIJA (02T)   
  
Vilnius  
 
 2011
 
Disertacija rengta 2006–2011 metais Vilniaus Gedimino technikos universitete.  Mokslinis vadovas prof. habil. dr. Romualdas MAČIULAITIS Gedimino (Vilniaus technikos universitetas, technologijos mokslai, statybos inžinerija – 02T). Konsultantas doc. dr. Ramun ŽURAUSKIE(Vilniaus Gedimino technikos universitetas, technologijos mokslai, statybos inžinerija – 02T). Disertacija ginama Vilniaus Gedimino technikos universiteto Statybos inžinerijos mokslo krypties taryboje: Pirmininkas prof. dr. Povilas VAIIŪAS(Vilniaus Gedimino technikos universitetas, technologijos mokslai, statybos inžinerija – 02T). Nariai: prof. habil. dr. Juozas ATKOČIŪAS (Vilniaus Gedimino technikos universitetas, technologijos mokslai, statybos inžinerija – 02T), doc. dr. Darius BAČISKAS(Vilniaus Gedimino technikos universitetas, technologijos mokslai, statybos inžinerija – 02T), dr. Mindaugas DAUKŠYS(Kauno technologijos universitetas, technologijos mokslai, statybos inžinerija – 02T), prof. habil. dr. Vytautas STAKEVIČIUS(Kauno technologijos universitetas, technologijos mokslai, statybos inžinerija – 02T). Oponentai: prof. habil. dr. Stasys BOČKUS(Kauno technologijos universitetas, technologijos mokslai, medžiagų inžinerija – 08T), doc. dr. Gintautas SKRIPKIŪAS(Vilniaus Gedimino technikos universitetas, technologijos mokslai, statybos inžinerija – 02T).  Disertacija bus ginama viešame Statybos inžinerijos mokslo krypties tarybos posdyje 2012 m. sausio 6 d. 13 val. Vilniaus Gedimino technikos universiteto senato posdžių salje. Adresas: Saultekio al. 11, LT-10223 Vilnius, Lietuva. Tel.: (8 5) 274 4952, (8 5) 274 4956; faksas (8 5) 270 0112; el. paštas doktor@vgtu.lt Disertacijos santrauka išsiuntinta 2011 m. gruodžio 5 d. Disertaciją galima peržiūrti Vilniaus Gedimino technikos universiteto bibliotekoje (Saultekio al. 14, LT-10223 Vilnius, Lietuva). VGTU leidyklos „Technika“ 1943-M mokslo literatūros knyga. © Marija Vaičien, 2011
 
 
Inrtoduction  Topicality of the problem– there are some scientific research carried out in the field of lightweight concrete since 1960. Scientists are focused on the selection of the raw materials, additives, their characteristics, technologies for the production of expanded-clay lightweight concrete, formation of the products, compaction modes, thermal processing modes etc. Currently it is especially topical to produce the lightweight concrete by utilising various raw materials. Therefore, two active mineral additives were selected: catalyst from the reactor of catalytic oil cracking (CAT) and unburned mullite wool (MW). The possibilities thereof to be utilised in the processing of expanded-clay lightweight concrete are not analysed so far.  Research object influence of the active mineral additives (catalyst from the reactor of catalytic oil cracking and unburned mullite wool) on the main characteristics of the expanded-clay lightweight concrete (density, compressive strength, water impregnation etc.).  Aim of the workis to analyse the active mineral additives, formed in the reactor of catalytic oil cracking (CAT) and during the smoothing of unburned mullite wool panels (MW), to utilise this waste in the compositions of expanded-clay lightweight concrete and to determine the influence of active mineral additives on the properties of the expanded-clay lightweight concrete and to choose the composition of the mixtures of expanded-clay lightweight concrete with the additive of these waste materials and determination the possible utilisation of waste materials are also a part of the objective. To achieve the objectives of the research, the followingtasksmust be solved: 1. Analysis of the properties of used raw materials and active mineral additivesunground catalyst from the reactor of catalytic oil cracking and unburned, undispersed mullite wool. 2. of the amount of the active additives ofIdentification of the influence active mineral additives on the physical and mechanical properties of the expanded-clay lightweight concrete. 3. Analysis of the influence of the active mineral additives on the technology of cement hydration in the compositions products. 4. Identification of the main and derivative structural parameters of the samples with additives of expanded-clay lightweight concrete, prediction of exploitative frost resistance. 5. Selection of the best amounts of waste materials of unground catalyst from the reactor of catalytic oil cracking and unburned, undispersed
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mullite wool, in the mixtures of expanded-clay lightweight concrete based on the research results.  Methodology of research. the investigation of the properties of raw For materials and samples, used in the research, the physical and mechanical analysis based on the standard methodologies was carried out for the investigation of the structure, optical microscopy, scanning electronic microscopy (SEM), X-ray analysis and exothermic analysis methodologies were applied.  Scientific novelty. possibility to produce the expanded-clay The lightweight concrete products from Portland limestone cement, natural sand, expanded clay sand, as well as from active mineral CAT and MW additives, was identified. For the first time the durability of the samples of expanded-clay lightweight concrete with the additives of CAT and MW waste was estimated in relation to the predicted exploitative frost resistance. Expanded-clay lightweight concrete with sufficient strength and low density was developed by using CAT waste and lower amount of cement. Certain peculiarities of cement hydration in the mixtures of the expanded-clay lightweight concrete with active mineral additives were identified.  Practical value expanded-clay lightweight concrete with best – compositions, when part of the cement is replaced by CAT and MW waste materials, can be used as constructional and heat insulation material for the construction of low-rise and high buildings and is suitable for aggressive climatic conditions in Lithuania.  Defended propositions 1. When raw materials (Portland limestone cement, natural sand, expanded-clay sand) and best amount of active mineral additives is used, after part of the cement is replaced by waste material of unground catalyst from the reactor of catalytic oil cracking, it is possible to produce such expanded-clay lightweight concrete, that would have higher amounts of the compressive strength and would be more frost resistant. 2. Waste material of unground catalyst from the reactor of catalytic oil cracking changes the hydration process of Portland cement in the mixtures of expanded-clay lightweight concrete. When the amount of the catalyst waste material is increased (until 30 %), the time required to reach the maximal temperature decreases.
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3. Unburned and undispersed mullite wool slows down the hydration process of Portland cement due to the shortage of water. However, mullite wool is suitable for the production of expanded-clay lightweight concrete with the lowered heat conduction ratio. 4. The amount of active mineral additives in the mixtures of expanded-clay lightweight concrete shall be optimised in accordance with tendency variations of the density, compressive strength, frost resistance and heat conduction ratio.  The scope of the scientific work. Dissertation is composed from the introduction, fours sections, general conclusions, lists of the reference literature and author's publications. Scope of research – 120 pages, 6 numbered equations, 50 pictures and 21 table used in the textual part. 170 reference sources were used for the preparation of dissertation.  1. Additives influence on the properties of expanded-clay lightweight concrete  The analysis of the literature shows, that it is possible to decrease price of expanded-clay lightweight concrete, some quantity of cement changing of active mineral additives. In the doctoral dissertation are analysing development of the expanded-clay lightweight concrete manufacture, mineral additives and types of active mineral additives, influence of additives on the properties of lightweight concrete and possibilities of mineral additives from waste materials utilization. Also is analysing nemaline additives and resistance to frost of expanded-clay lightweight concrete. It was not found experimental results of using the catalyst waste from the reactor of catalytic oil cracking and unburned waste material of mullite wool in the expanded-clay lightweight concrete. Mostly these additives are used in ceramics, fire-resistant concrete, etc.  2. Used raw materials and research methodology  The following main raw materials were used to achieve the formulated work's tasks: 1. Portland limestone cement CEM II/A-LL 42,5 N, from JSC „Akmens cementas“. Chemical composition of Portland limestone cement [in mass %]: SiO2 Al – 63,42, CaO– 20,61,2O3– 5,45, Fe2O3 – 3,84,– 3,36, MgO SO32- others – 2,18. CaO – 0,73,– 0,80, Mineral composition of Portland limestone cement [in mass %]: C3S – 57,26, C2S – 15,41, C3A – 8,68, C4AF – 10,15.
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2. Natural sand of 0/4 fraction, Rizgoniai quarry (Ukmergs district.). Sand bulk density – 1620 kg/m3, particles' density – 2614 kg/m3, hollowness – 40 %, module of coarseness – 2,22. 3. JSC „Saint-Gobain statybos gaminiai“ „Fibo“ expanded-clay sand with the fraction of 2/4. Expanded-clay sand: bulk density – 473 kg/m3, particles' density – 1020 kg/m3, hollowness – 53,63 %, impregnation – 33,55 %. 4. In the company JSC „ORLEN Lietuva“ obtained unground fine-grained catalyst waste from the reactor of catalytic oil cracking (CAT). The chemical composition of this catalyst waste is as follows: SiO2– 55,15%, Al2O3– 40,94%, Fe2O3 TiO– 0,90%,2– 1,48%, P2O5 La– 0,11%,2O3– 1,41%. The remains of the following materials exist as well: CaO, MgO, K2O and Na2The particle size of the catalyst waste varies from 0,2 to 112 m. The X-O. ray diffraction analysis was employed to identify the crystal structure of the catalyst. It was zeolite Y with the distinctive crystal structure of faujasite.  
 Fig. 1.Microstructure view of the catalyst's particles  Shape of the catalyst waste material from the reactor of catalytic cracking is spherical (Fig. 1). Utilised catalyst (code 16 08 04) belongs to the group of non-hazardous materials in European Waste Catalogue. 5. Other waste material utilised – unburned waste material of mullite wool (MW), produced in company JSC „Umega“. Unburned slab waste, produced during the polishing, was used in the research. Scanning electron microscope was used to analyse the strings of the unburned mullite wool (Fig. 2 a). In addition to the strings, beads are found in the mullite wool as well. After zooming in by 8000 times (Fig. 2 b), it was identified that the surface of the strings is almost ideally smooth. 6. Drinking water was used for the mixtures of expanded-clay lightweight concrete. Samples with the size of 100×100×100 mm were formed to determine physical and mechanical properties of the expanded-clay lightweight concrete. 8  
Samples were prepared and hardened in accordance with LST EN 12390-2:2009 standard. Main properties of the expanded-clay lightweight concrete were determined in accordance with 12390 serial standards.  a) b)
   Fig. 2.Microstructure of the strings of the unburned mullite wool  Catalyst waste, microstructure of mullite wool and prepared samples of expanded-clay lightweight concrete were analysed by scanning electron microscope SEM (EVO LS 25, Zeiss Germany). X-ray diffraction analysis was implemented by using diffraction meter DRON-7. Temperature variations during binding and hardening of the concrete were estimated according to the methodology developed by company “Alcoa”. Structural parameters and forecasted exploitative frost resistance (in conditional cycles) of the samples of expanded-clay lightweight concrete were determined and calculated. Active additives CAT and MW replace the corresponding amount of cement in the mixtures. Compositions of formation mixtures of the samples of expanded-clay lightweight concrete, when CAT waste is used, are provided in Table 1. Compositions of formation mixtures of the samples of expanded-clay lightweight concrete with MW waste are provided in Table 2. All the investigated concrete mixtures depends to S1 slump class (slump from 10 to 40 mm).  3. Results of the analysis of expanded-clay lightweight concrete with catalyst waste  When different amounts of CAT waste were used in the mixture, expanded-clay lightweight concrete with various densities and compressive strengths was produced. Results of the analysis show (Fig. 3) that, when different amounts of CAT additive are used during the preparation of 9  
 
Table 1.Compositions of expanded-clay lightweight concrete mixtures with CAT Amounts of materials for 1 m3of concrete mixture, kg Mixture amount of catalyst, % ent expsaanndde 2d/-4c lay sand 0/4 water catalyst marking cem
K0 0 427 312 648 221 – K1 3 413 311 644 220 12 K2 5 410 315 653 223 21 K3 10 380 309 640 219 42 K4 15 379 325 675 230 66 K5 20 342 312 646 221 84 K6 30 314 328 681 232 135
Table 2.of expanded-clay lightweight concrete mixtures with MWCompositions Amounts of materials for 1 m3of concrete mixture, kg mMairxktiunreg  ammouullnitt eo f cement expanded-clay sand 0/4 water mullite wool wool % sand 2/4 , MV0 0 MV1 5 MV2 10 MV3 15 MV4 20
371 327 323 257 229
353 731 192 327 678 178 341 707 186 288 597 156 272 565 148
 17 36 45 57
W/C
0,52 0,53 0,54 0,57 0,61 0,65 0,74
W/C
0,52 0,54 0,57 0,61 0,65
 
 
expanded-clay lightweight concrete, density varies from 1371 to 1458 kg/m3.  1600 1387 1380 1399 1371 1445 1384 1458 1400 1200 1000 800 600 400 200 0 K0 K1 K2 K3 K4 K5 K6  Fig. 3. Average density values of the expanded-clay lightweight concrete samples with CAT waste: K0 – without waste; K1 – with 3%of waste; K2 – with 5%of waste; K3 – with 10%of waste; K4 – with 15%of waste; K5 – with 20%of waste; K6 – with 30%of waste  In dissertation, during the analysis the compressive strength of the samples of expanded-clay lightweight concrete was determined after 2, 14 and 28 days of hardening. Average values of the compressive strength, identified during the experimental investigations, are provided in Fig. 4.  20 18K0 16K1 14 12K2 10K3 8K4 6 4K5 2K6 0 2 14 28 Time, days  Fig. 4.Average compressive strength values of the expanded-clay lightweight concrete samples with CAT waste: K0 – without waste; K1 – with 3%of waste; K2 – with 5% of waste; K3 – with 10%of waste; K4 – with 15%of waste; K5 – with 20%of waste; K6 – with 30%of waste  Results of further analysis show (Fig. 4 after 28 days of hardening) that average compressive strength of the samples produced from the reference mixture is 16,4 MPa.
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