Experimental Study and Performance Analysis of Concrete Shrinkage-Reducing Agents

2011 ◽  
Vol 311-313 ◽  
pp. 1879-1883
Author(s):  
Yong Cun Zhang ◽  
Qing Ning Li
Keyword(s):  
Drying Shrinkage ◽  
High Strength ◽  
Butyl Alcohol ◽  
Reducing Agents ◽  
Chemical Components ◽  
Concrete Shrinkage ◽  
Mortar Strength ◽  
Tert Butyl Alcohol ◽  
Concrete Blocks ◽  
And Performance

This paper will focus on developing a sort of concrete shrinkage-reducing agents that are generally some surfactants on the basis of some tests. By reference to the main chemical components of some domestic and foreign agents, the following chemicals are initially selecting : tert-butyl alcohol, triethanolamine and polyvinyl alcohol, and then some experiments about these substances were made, including liquid surface tension test, high-strength cement mortar shrinkage test, mortar strength test. Finally, the medicals that can significantly reduce drying shrinkage deformation but have little effect on the strenth of concrete blocks,are selected out as available concrete shrinkage-reducing agents.

scholarly journals A discussion for the reduction in the length of a prestressed concrete railway tie in time

2021 ◽  
Author(s):  
Niyazi Özgür Bezgin
Keyword(s):  
Prestressed Concrete ◽  
High Strength ◽  
Railway Track ◽  
Structural Elements ◽  
Track Maintenance ◽  
Concrete Shrinkage ◽  
Prestressing Force ◽  
Steel Wires ◽  
Practical Evaluation ◽  
And Performance

Increasing train speeds, contemporary requirements for reduced track maintenance costs and extended track service lives required the development and use of reinforced concrete and prestressed concrete ties. Railway engineers began to use concrete for their bi-block and monoblock railway ties heavily, following the development of an understanding for design and performance of concrete structures, production of high strength steel wires and preferable economy of prefabricated mass production for reinforced and prestressed concrete structural elements following the first half of 20th Century. Structural elements of a railway track such as reinforced or prestressed concrete ties have strict production tolerances that are not common for ordinary structural elements. Production of concrete railway ties takes place under strict dimensional control that ensures a nominal design gauge width for the railway track. Design specifications for prestressed monoblock ties frequently specify the gauge width and the shoulder width to be within 1 mm of the design width. However, prestressed concrete ties experience shortenings in length due to transfer of the prestressing force known as instant elastic shortening and shortenings due to concrete shrinkage and concrete creep in time that also relate to ambient relavite humidity. The author conducted numerous studies on the matter, showed by calculation, and observed experimentally that if unaccounted for, such shortenings can surpass the allowed tolerances in time and result in the rejection of the produced tie for use in the railway track. This paper refers to previous studies by the author that brought international attention on the issue and presents a thorough and a practical evaluation of time related changes in tie lengths for a particular design for prestressed concrete monoblock ties under varying ambient humidity conditions.

Fabrication, Structure and Properties of Porous SiC Ceramics with High Porosity and High Strength

2010 ◽  
Vol 105-106 ◽  
pp. 608-611 ◽  
Author(s):  
Shao Feng Wang ◽  
Chang An Wang ◽  
Jia Lin Sun ◽  
Li Zhong Zhou ◽  
Yong Huang
Keyword(s):  
Compressive Strength ◽  
High Strength ◽  
Butyl Alcohol ◽  
Solid Loading ◽  
High Porosity ◽  
Reaction Bonding ◽  
Sintering Additive ◽  
Sic Ceramics ◽  
Tert Butyl Alcohol ◽  
Porous Sic

Porous SiC ceramics with high porosity and high strength were fabricated by gelcasting, with tert-butyl alcohol (TBA) as solvent, acrylamide (AM) as monomer, and in-situ reaction bonding with a-Al2O3 as sintering additive. SiC suspension with 10 vol% solid loading was successfully solidified by gel-casting to form high strength green body. The results showed that the compressive strength of the porous SiC ceramics increased with sintering temperature from 1300 to 1450°C, but porosity had little change, due to formation of more volume of cristobalite and mullite phases on the surface of SiC grains, accompanied by a large volume expansion effect. Very narrow single-peak distributions with about 2 mm median pore diameter could be found for the porous SiC ceramics. The porosity and compressive strength of the porous SiC ceramics sintered at 1450°C were 71.21 % and 12.14 MPa, respectively.

Experimental Investigation of the Shrinkage Performance of Small Blocks Made by Rock Chips Concrete

2013 ◽  
Vol 857 ◽  
pp. 64-69
Author(s):  
Jie Yuan ◽  
De Min Feng ◽  
Fu Ming Liu ◽  
Yong Quan Zhang ◽  
Yang Liu
Keyword(s):  
Drying Shrinkage ◽  
High Strength ◽  
Steam Curing ◽  
Strength Performance ◽  
Opposite Change ◽  
Concrete Blocks ◽  
Curing Methods ◽  
New Type ◽  
Water Curing ◽  
Main Component

A new type of small concrete blocks with high strength performance was generated in this study, and the main component of this kind of small blocks were made by the MU15.0 that was extracted from the waste rock chips. The effect of content of stone powder and the different curing methods on the shrinkage of the proposed concrete blocks, was investigated by using the experimental method. The results showed that (i) with the increase of the amount of stone power, the drying shrinkage of rock chips concrete went up at first, and then the opposite change was generated; (ii) The small hollow blocks made by the rock chips concrete after steam curing kiln, under the condition of enough water curing and seal environment, had higher compressive strength and smaller shrinkage comparing with other curing methods.

Thermodynamic and Kinetic Investigation of the Solvent Effect on the Oxidation of [Co(en)2SCH2COO]+ with S2O82- In Water-Methanol and Water-tert-Butyl Alcohol Mixtures

1993 ◽  
Vol 58 (5) ◽  
pp. 1001-1006 ◽  
Author(s):  
Oľga Vollárová ◽  
Ján Benko
Keyword(s):  
Transfer Functions ◽  
Activation Parameters ◽  
Butyl Alcohol ◽  
Oxidation Of Co ◽  
Kinetics Of Oxidation ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Alcohol Mixtures ◽  
Kinetics Of

The kinetics of oxidation of [Co(en)2SCH2COO]+ with S2O82- was studied in water-methanol and water-tert-butyl alcohol mixtures. Changes in the reaction activation parameters ∆H≠ and ∆S≠ with varying concentration of the co-solvent depend on the kind of the latter, which points to a significant role of salvation effects. The solvation effect on the reaction is discussed based on a comparison of the transfer functions ∆Ht0, ∆St0 and ∆Gt0 for the initial and transition states with the changes in the activation parameters accompanying changes in the CO-solvent concentration. The transfer enthalpies of the reactant were obtained from calorimetric measurements.

Transfer Thermodynamic Functions ∆Gt0, ∆Ht0 and T∆St0 of cis- and trans-[CoCl2(en)2]+ Isomers in Aqueous Mixtures of Methanol, tert-Butyl Alcohol and Acetonitrile

2000 ◽  
Vol 65 (9) ◽  
pp. 1455-1463
Author(s):  
Oľga Vollárová ◽  
Ján Benko
Keyword(s):  
Enthalpy Of Solution ◽  
Transfer Functions ◽  
Partial Molar Volumes ◽  
Butyl Alcohol ◽  
Aqueous Mixtures ◽  
Aqueous Methanol ◽  
Solvent Interactions ◽  
Tert Butyl Alcohol ◽  
Surface Charge Distribution ◽  
Cis And Trans

The solubility, partial molar volume and standard integral molar enthalpy of solution of cis- and trans-[CoCl2(en)2]Cl in water, aqueous methanol, aqueous tert-butyl alcohol and aqueous acetonitrile are reported. The transfer functions ∆Gt0, ∆Ht0 and T∆St0 as well as partial molar volumes are used to obtain information on the solute-solvent interactions. Results obtained are discussed in terms of differences in the surface charge distribution in isomeric coordination species.

scholarly journals Efficient Degradation of Mordant Blue 9 Using the Fenton-Activated Persulfate System

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2532 ◽  
Author(s):  
Md. Nahid Pervez ◽  
Felix Y. Telegin ◽  
Yingjie Cai ◽  
Dongsheng Xia ◽  
Tiziano Zarra ◽  
...  
Keyword(s):  
Butyl Alcohol ◽  
Textile Dye ◽  
Oh Radicals ◽  
Operational Parameters ◽  
Reaction Conditions ◽  
Tert Butyl Alcohol ◽  
Initial Ph ◽  
Fe Complex ◽  
Optimal Reaction ◽  
Activated Persulfate

In this study, a Fenton-activated persulfate (Fe2+/PS) system was introduced for the efficient degradation of Mordant Blue 9 (MB 9) as a textile dye in an aqueous solution. Results showed that the degradation of MB 9 was markedly influenced by operational parameters, such as initial pH, PS concentration, Fe2+ concentration, and initial dye concentration. Optimal reaction conditions were then determined. Inorganic anions, such as Cl− and HCO3−, enhanced the degradation efficiency of MB 9 under optimal conditions. Addition of HCO3− reduced the degradation performance of MB 9, whereas the addition of Cl− increased the degradation percentage of MB 9. In addition, quenching experiments were conducted using methanol and tert-butyl alcohol as scavengers, and methanol was identified as an effective scavenger. Thus, the degradation of MB 9 was attributed to S O 4 • − and •OH radicals. The degradation and mineralization efficiency of MB 9 was significantly reduced using the conventional Fenton process i.e., Fe2+/ hydrogen peroxide (HP) because of the formation of a Fe complex during degradation. Meanwhile, the Fe2+/persulfate (PS) system improved the degradation and mineralization performance.

scholarly journals Impacts of Sn(II) doping on the Keggin heteropolyacid-catalyzed etherification of glycerol with tert-butyl alcohol

2021 ◽  
pp. 116913
Author(s):  
Márcio José da Silva ◽  
Diego Morais Chaves ◽  
Sukarno Olavo ferreira ◽  
Rene Chagas da Silva ◽  
Jose Balena Gabriel Filho ◽  
...  
Keyword(s):  
Butyl Alcohol ◽  
Tert Butyl ◽  
Tert Butyl Alcohol

scholarly journals Manufacturing and development of a bolted GFRP flange joint for oil and gas applications

2021 ◽  
pp. 095440542198951
Author(s):  
Muhsin Aljuboury ◽  
Md Jahir Rizvi ◽  
Stephen Grove ◽  
Richard Cullen
Keyword(s):  
Pressure Vessel ◽  
Oil And Gas ◽  
Polyester Resin ◽  
High Strength ◽  
Adhesively Bonded ◽  
Acceptable Quality ◽  
Composite Pipe ◽  
And Performance ◽  
Composite Pipes

The goal of this experimental study is to manufacture a bolted GFRP flange connection for composite pipes with high strength and performance. A mould was designed and manufactured, which ensures the quality of the composite materials and controls its surface grade. Based on the ASME Boiler and Pressure Vessel Code, Section X, this GFRP flange was fabricated using biaxial glass fibre braid and polyester resin in a vacuum infusion process. In addition, many experiments were carried out using another mould made of glass to solve process-related issues. Moreover, an investigation was conducted to compare the drilling of the GFRP flange using two types of tools; an Erbauer diamond tile drill bit and a Brad & Spur K10 drill. Six GFRP flanges were manufactured to reach the final product with acceptable quality and performance. The flange was adhesively bonded to a composite pipe after chamfering the end of the pipe. Another type of commercially-available composite flange was used to close the other end of the pipe. Finally, blind flanges were used to close both ends, making the pressure vessel that will be tested under the range of the bolt load and internal pressure.

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