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Ultra-High Strength Concrete Mixtures Using Local Materials

Journal of Civil Engineering and Architecture 2011年第4期5卷 322-330页

作者： srinivas allena Craig M. Newtson Civil and Environmental Engineering Department Washington State University Tri-Cities Richland WA 99354 USA Civil Engineering Department New Mexico State University Las Cruces NM 88003 USA

This paper presents the development of ultra high strength concrete (UHSC) using local materials. UHSC mixture proportions were developed using local materials so that UHSC may be made more affordable to a wider variety of applications. Specifically, local sand with a top size of 600 μm, and locally available Type I/II cement and silica fume were used in this research. Each of these material selections is seen as an improvement in sustainability for UHSC. Two mixtures (one with and one without fibers) were recommended as the UHSC mixtures. The greatest compressive strengths obtained in this study were 165.6 MPa for UHSC with steel fibers and 161.9 MPa for UHSC without fibers. The compressive and flexural strengths obtained from the UHSC mixtures developed in this work are comparable to UHSC strengths presented in the literature. Producing this innovative material with local materials reduces the cost of the material, improves sustainability, and produces mechanical performance similar to prepackaged, commercially available products.

关键词：超高强度混凝土新材料混合物抗压强度可持续发展开发利用混合比例可持续性

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Developing Sustainable Ultra High Strength Concrete Mixtures Using Spent Foundry Sand

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Journal of Civil Engineering and Architecture 2019年第6期13卷 343-352页

作者： Anthony Torres Federico Aguayo srinivas allena Department of Engineering Technology Texas State UniversitySan Marcos 78666TexasUSA Department of Civil Engineering Cleveland State UniversityCleveland 44115OhioUSA

This study presents the development of ultra high strength concrete(UHSC)that has been made more sustainable by using both local materials from central Texas and spent foundry sand(FS)from the metal casting industry,which has also been obtained *** study first describes various trial mixtures tested as well as the specimen preparation techniques investigated that led to the final UHSC-FS *** developed mixtures were proportioned with local constituents to increase the sustainable impact of the material by reducing emissions due to shipping as well as making UHSC more affordable to a wider variety of *** final mixture design constituents were:river sand,locally available type I/II cement,silica fume,and spent FS,which was obtained from a local steel casting *** variables were investigated,such as the aggregate type and size,concrete age(7,14,and 28-days),the curing regimen,and the water-to-cement ratio(w/cm)to optimize a UHSC mixture that used local materials and *** systematic development revealed that heat curing the specimens in a water bath at 50 oC(122 oF)after demolding and then dry curing at 200 oC(392 oF)two days before testing with a w/cm of 0.20 at 28-days produced the highest compressive *** an optimum UHSC mixture was identified a partial replacement of the fine aggregate with FS was completed at 10%,20%,and 30%.The results showed an increase of compressive strength performance at 10%replacement,followed by no change at 20%,and finally a slight decrease at 30%.Developing this innovative material with local materials and FS ultimately produces a novel sustainable construction material,reduces the costs,and produces mechanical performance similar to prepackaged,commercially,available construction building materials.

关键词： High strength concrete sustainability recycled concrete aggregate local products construction materials

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The Effect of Various Polynaphthalene Sulfonate Based Superplasticizers on the Workability of Reactive Powder Concrete

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Journal of Building Material Science 2020年第1期2卷 24-29页

作者： Anthony Torres Federico Aguayo srinivas allena Michael Ellis Texas State University San MarcosTX78666 Cleveland State University Cleveland44115

A superplasticizer is a type of chemical admixture used to alter the workability(viscosity)of fresh *** workability of fresh concrete is often of particular importance when the water-to-cement(w/c)ratio is low and a particular workability is *** Powder Concrete(RPC)is a high-strength concrete formulated to provide compressive strengths exceeding 130MPa and made of primarily *** materials typically have a very low w/c,which requires the use of a chemical admixture in order to create a material that is easier to place,handle and *** are commonly used for this *** are developed from different formulations,the most common being Polycarboxylate Ether(PCE),Polymelamine Sulfonate(PMS),and Polynaphthalene Sulfonate(PNS).This study investigates the effect of various PNS based superplasticizers on the rheological performance and mechanical(compressive strength)performance of a RPC *** distinctive types of PNS based superplasticizers were used;three of various compositional strengths(high,medium,low range)from a local provider,and three of the same compositional strengths(high,medium,low)from a leading *** properties investigated were the individual superplasticizers’viscosity,the concrete workability,determined through a mortar spread test,the concrete viscosity,and the compressive strength of the hardened RPC mixtures measured at 7,14,and 28 *** separate RPC mixtures were prepared,which contained two different water-to-cementitious ratios,which consequently increases the dosage of superplasticizer needed,from 34.8L/m3 to 44.7L/*** results show that the name brand high range composition produced the overall highest spread,lowest viscosity,and a highest compressive ***,the local provider outperformed the name brand in the mid and low range ***,the rheology assessment also confirmed that the name brand high range,and RPC fabricated with the n

关键词： Reactive powder concrete Ultra high strength concrete Superplasticizer Workability

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Freezing and Thawing Durability of Ultra High Strength Concrete

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Journal of Civil Engineering and Architecture 2013年第8期7卷 907-915页

作者： Jesus Muro-Villanueva Craig M. Newtson Brad D. Weldon David V. Jauregui srinivas allena Civil Engineering Department New Mexico State University Las Cruces NM88003 USA Civil and Environmental Engineering Department Washington State University Richland WA 99354 USA

Resistance to freezing and thawing of two UHSC (ultra high strength concrete) mixtures was evaluated in accordance with ASTM C 666 Procedure A. The two mixtures (plain and fiber reinforced) were developed using materials local to southern New Mexico, USA. Three different curing regimens were investigated for the mixture with fibers and one curing regimen was studied for the mixture without fibers. All curing regimens included 24 h of ambient curing followed by four days of wet curing at 50 oC, and then two days dry curing at 200 oC. At an age of seven days, one batch of fiber reinforced specimens was air cured at ambient conditions for the following six days and then placed in a water bath at 4.4 oC for 24 h prior to initiating freezing and thawing cycles. The second batch was air cured from day seven to day 12, and then wet cured for one day at 23 oC prior to being placed in the 4.4 oC water bath. The final batch was wet cured at 23 oC from the seventh day to an age of 13 days and then placed in the 4.4 oC water bath. The mixture with no fibers was air cured from the seventh day to an age of 12 days and then wet cured for one day at 23 oC prior to being placed in the 4.4 oC water bath. Higher moisture levels during curing produced greater initial dynamic elastic modulus values and durability factors at the end of the freezing and thawing tests, with the greatest durability factor being 87.5. Steel fibers were observed to improve both compressive strength and durability factor for UHSC.

关键词：冻融耐久性超高强度混凝土纤维增强超高强混凝土动态弹性模量湿固化新墨西哥州高抗压强度

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