Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Civil and Environmental Engineering." Includes bibliographical references (p. 151-153).

Concrete is one of the world's most widely used building materials,but due to the high carbon dioxide emissions produced by the concretecomponent Portland cement, there is a growing need of alternativeconcrete recipes that require less portland cement. When you replace aportion of the Portland cement in the concrete recipe with an additivematerial such as granulated blast furnace slag, the carbon dioxideemissions decrease, but the strength growth becomes slower. Inconcrete casting, there are currently several working methods foraccelerating strength growth and the purpose of this work is toinvestigate the effect that various hardening accelerating measureshave on slag-based concrete. The work is limited to studying buildingproduction and focuses on the structural parts concrete slabs, wallsand filigree slabs. The study was carried out in collaboration withSkanska AB.To investigate the effect of different hardening accelerating measureson slag-based concrete, concrete casting simulations are compared inthe software Produktionsplanering Betong (PPB). The measures that arestudied in different variations are heating coils, external heating,insulation and elevated casting temperature. A total of 114simulations are planned, which include variations of the investigatedmeasures, outdoor temperature and design geometry. A survey is alsoconducted with the purpose to assess how hardening acceleratingmeasures are applied in swedish building production today. The surveyis spread with a geographical spread to five of the largesthouseproducing construction groups in Sweden. The result of thesimulations performed is that the measure heating loops has achievedthe best result where its effect has been optimized for eachindividual case. The results indicate that heating coils, incombination with insulation, are an effective measure. At the sametime, the survey shows that there is annoyance with the methods thathave proven effective in the simulations performed. Although it is notpossible to draw a conclusion about a universal solution to compensatefor the slower hardening time of the slag concrete, the results stillindicate that today's construction industry has good conditions for atransition to a more environmentally friendly concrete. / Betong är ett av världens mest använda byggmaterial, men på grund av den stora haltkoldioxidemissioner betongkomponenten cement producerar så finns ett ökandebehov att tillämpa betongrecept som kräver mindre cement. Då man ersätter en andelav portlandcementet i betongreceptet med ett alternativt tillsatsmaterial somgranulerad masugnsslagg, minskar koldioxidemissionerna, men hållfasthetstillväxtenblir långsammare. Vid betonggjutning finns i dag flera arbetsmetoder för att påskyndahållfasthetstillväxten och syftet med detta arbete är att undersöka vilken effekt dessaolika härdningspåskyndande åtgärder har på slaggbaserad betong, även kalladslaggbetong. Arbetet begränsas till att studera husproduktion och fokuserar påkonstruktionsdelarna platta på mark, väggelement och filigranbjälklag. Studien ärutförd i samarbete med Skanska Sverige AB.För att undersöka vilken effekt olika härdningspåskyndande åtgärder har påslaggbetong jämförs betonggjutningssimuleringar i programvaranProduktionsplanering Betong, (PPB). Slaggbetongen som undersöks är Skanska GrönBetong, och åtgärderna som huvudsakligen studeras är olika variationer avvärmeslingor, extern uppvärmning, isolering och höjd gjutningstemperatur. 114stycken simuleringar planeras totalt, vilka inkluderar variationer av de undersöktaåtgärderna, uteluftstemperatur och konstruktionsgeometri. En enkätundersökningutförs även med syfte att bedöma hur härdningspåskyndande åtgärder tillämpas isvensk husproduktion idag. Enkäten sprids med en geografisk spridning till fem avde största husproducerande byggkoncernerna i Sverige. Resultatet av de utfördasimuleringarna är att åtgärden värmeslingor uppnått bäst resultat där dess effekt varitoptimerad för varje enskilt fall. Resultatet tyder på att värmeslingor i kombinationmed isolering, är en effektiv åtgärd. Samtidigt visar enkätundersökningen att det finnserfarenhet av de metoder som visat sig effektiva i de simuleringar som utförts. Trotsatt det ej går att dra en slutsats om en allmängiltig lösning för att kompensera förslaggbetongens långsammare härdningstid, tyder ändock resultatet på att dagensbyggindustri har goda förutsättningar för en övergång till en miljövänligare betong.

The eco-friendly alternatives use is increasing momentum in a conscious effort towards sustainability. In this regards, the relevance and the economic value of using copper slag as a concrete aggregate are explored in this study in order to contribute towards metallurgical waste recycling. Emphasis is placed on the evaluation of the concretes strengthening prepared with copper slag contents and produced under four curing methods: water immersion, water spraying, plastic sheet covering and air-drying. In each curing case excluding for water immersion, was duplicated in indoors (i.e. in the laboratory) and outdoor exposure (so was prone to varying environmental conditions). This was specifically aimed at capturing the effects of tropical weather conditions typical of the Lualaba province in the Democratic Republic of Congo. The control mix was designed to reach 25 MPa of compressive strength. Copper slag was successively incorporated as sand replacement at the following mass fractions: 20 %, 40 % and 60 %. Freshly mixed concrete samples were evaluated for workability. Cube specimens were cast accordingly, cured for 28 days and then tested for density and compressive strength. Results indicated an increase in strength up to 20 % of replacement rate for all the curing methods. Further additions resulted in reduction in the strength, but the rate of reduction depended on curing conditions. The increase in strength was mainly credited to the physical properties of copper slag that could have contributed to the cohesion of the concrete matrix. It has been found that appropriate ways of curing can still achieve greater results than that of the control mix since 80 % of humidity is ensure. The two-way ANOVA test performed on the 28-days compressive strength values confirmed the significant influence of the curing methods, of copper slag content and the interaction between them. It has been found that considerable influence is attributed to copper slag content and that warm environmental conditions further extend the concrete strengthening. / College of Engineering, Science and Technology / M. Tech. (Chemical Engineering)