The rapid growth of economy and the recent development of industry in Lithuania have considerably increased, and therefore the need for industrial concrete floors also has a tendency to growing. The floor is used in almost all industrial companies because of differently modified concrete and a number of coating materials. It is more difficult to make an effective solution for choosing the required coating due to the supply of many different coating materials, an improvement in technological solutions, stiffening economic and ergonomic requirements. The article focuses on the complex problems of working towards a solution for selecting coating, presents the evaluation of conditions for floor exploitation and analyses mistakes and economic outcomes. The paper describes the expedience and problems of evaluating solutions for choosing floor covering in terms of reliability, makes the complex model of factors that influence reliability and presents a practical example of calculating statistical reliability. Santrauka Spartejant ekonominiam ūkio vystymuisi ir plečiantis pramonei per pastaruosius metus Lietuvoje smarkiai išaugo ir ateityje turi tendencija augti pramoniniu betoniniu grindu poreikis. Šios grindys del ivairiai modifikuojamo betono ir gausaus skirtingu dangu medžiagu pasirinkimo šiuo metu naudojamos beveik visose pramones imonese. Esant gausiai ivairiu dangu medžiagu pasiūlai, tobulejant technologiniams sprendimams, griežtinant ekologinius, ergonominius reikalavimus, priimti efektyvu dangos sprendima vis sunkiau. Šiame straipsnyje nagrinejamos sudetingos dangu sprendimu priemimo problemos, pateikiamas eksploatacines dangu būkles ivertinimas, analizuojamos daromos klaidos ir ekonomines padarytu klaidu pasekmes grindis naudojančioms imonems. Nagrinejamas tikslingumas ir problematika priimtu grindu sprendimu vertinimo patikimumo aspektu, pateikiamas sudarytas patikimuma veikiančiu veiksniu kompleksinis modelis bei praktinis statistinio patikimumo skaičiavimo pavyzdys.
The exploitation time and reliability of monolithic reinforced concrete structures largely depend on concreting technology and process influence during concreting and early setting stages. Different types of cracks in monolithic reinforced concrete structures appear due to internal and external effects. Cracks appear when the technology of structure concreting is damaged, when formwork is removed during the further setting and structures loaded period. In order to avoid micro and macro cracks in monolithic structures, it is important to measure the particular setting time moment and technological process moment when stresses that exceed the permissible values appear in concrete. The article analyses the processes that appear when horizontal, sloping and vertical monolithic reinforced concrete structures are concreted. The analysis of concrete mixture pressure on formwork is performed. The pressure which is calculated according to different countries’ methodology is different: the smallest pressure is obtained calculating according to the British recommendations, and the largest pressure is obtained according to French CIB recommendations. In Lithuania, it is recommended to follow the German DIN 18218 standard. The balance conditions of concrete mixture concreting on slope surface are described. The main concreting technology parameters and their interaction are analysed; the speed, intensity and time of continuous concreting technology are presented. When the process of continuous concreting is performed, it is necessary to evaluate the interaction and values of parameters properly. Methodical theoretical calculation is presented. Practical solutions for industrial building construction applying the modern sliding formwork technology are presented. The impact of cement type, superplasticizers and temperature over the concrete mixture mobility, changes, fresh concrete structural strength and concrete setting kinetics are analysed. The main characteristics of the initial setting — the beginning of structure formation, when concrete mixture turns into concrete state — is analysed applying the ultrasonic method. The beginning of structure formation influences the regulated time of concrete mixture laying and compaction. The requirements for structural strength (permissible strength limits) and concreting rate (formwork movement) of freshly formed concrete are set when the construction is performed applying the continuous concreting technology method. The analysis is implemented performing the construction of cylindrical sludge tank with slipping formwork. While performing the analysis during concreting, it was stated that the concrete setting kinetics corresponds to the sludge tank concreting rate. The analysis performed after concreting and in 28 days of hardening revealed that there are no surface defects or cracks, and concrete strength exceeds the required sludge tank design strength. Santrauka Monolitinių gelžbetoninių statinių konstrukcijų eksploatacijos trukmė ir patikimumas daugiausia priklauso nuo betonavimo technologijos ir procesų poveikių betonavimo bei pradinio kietėjimo metu. Straipsnyje nagrinėjami procesai, vykstantys betonuojant horizontaliąsias, nuožulniąsias ir vertikaliąsias monolitines gelžbetonines konstrukcijas. Atlikta betono mišinio slėgio į formas analizė. Tiriami pagrindiniai betonavimo technologijos parametrai, analizuojamas jų ryšys, pateikiamas nepertraukiamo betonavimo technologijos betonavimo greitis, intensyvumas, trukmė. Atlikti teoriniai skaičiavimai ir siūlomi praktiniai sprendimai pramoninių statinių statybai, naudojant šiuolaikinę slankiųjų klojinių technologiją. Ištirta cemento tipo, superplastiklių, temperatūros įtaka šviežiai suformuoto betono struktūriniam stipriui ir betono kietėjimo kinetikai. Nustatyti reikalavimai šviežiai suformuoto betono struktūriniam stipriui, betonavimo greičiui (klojinių kėlimui), vykdant statybą nepertraukiamos betonavimo technologijos metodu. Tyrimai pritaikyti vykdant cilindrinio dumblo pūdytuvo statybą slankiaisiais klojiniais.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.