scholarly journals Performance Testing of Hydraulic Cements: Measuring Sulfate Resistance

Author(s):  
Chiara F. Ferraris ◽  
Paul E. Stutzman ◽  
Max Peltz

The sulfate resistance of cements used in the construction industry is traditionally assessed by measuring the expansion of a prism of 280 mm (11inch) length and 25 mm (1 inch) square cross section immersed in a sodium sulfate solution for at least one year. The duration of the experiment limits this test from being used as a performance-based determination of innovative mixtures of cementitious materials. In response to the need for a more rapid test protocol, the National Institute of Standards and Technology (NIST) has developed a new test method that measures the expansion of smaller bars (10 mm x 10 mm x 60 mm) made with neat cement paste. With these bars, similar expansion is achieved in less than 3 months, reducing the test duration by a factor of at least 4. This accelerated test method provides more rapid results consistent with the traditional test procedure, allowing for a shorter decision time and the screening of more materials.

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 686
Author(s):  
Amr Aboulela ◽  
Matthieu Peyre Lavigne ◽  
Amaury Buvignier ◽  
Marlène Fourré ◽  
Maud Schiettekatte ◽  
...  

The biodeterioration of cementitious materials in sewer networks has become a major economic, ecological, and public health issue. Establishing a suitable standardized test is essential if sustainable construction materials are to be developed and qualified for sewerage environments. Since purely chemical tests are proven to not be representative of the actual deterioration phenomena in real sewer conditions, a biological test–named the Biogenic Acid Concrete (BAC) test–was developed at the University of Toulouse to reproduce the biological reactions involved in the process of concrete biodeterioration in sewers. The test consists in trickling a solution containing a safe reduced sulfur source onto the surface of cementitious substrates previously covered with a high diversity microbial consortium. In these conditions, a sulfur-oxidizing metabolism naturally develops in the biofilm and leads to the production of biogenic sulfuric acid on the surface of the material. The representativeness of the test in terms of deterioration mechanisms has been validated in previous studies. A wide range of cementitious materials have been exposed to the biodeterioration test during half a decade. On the basis of this large database and the expertise gained, the purpose of this paper is (i) to propose a simple and robust performance criterion for the test (standardized leached calcium as a function of sulfate produced by the biofilm), and (ii) to demonstrate the repeatability, reproducibility, and discriminability of the test method. In only a 3-month period, the test was able to highlight the differences in the performances of common cement-based materials (CEM I, CEM III, and CEM V) and special calcium aluminate cement (CAC) binders with different nature of aggregates (natural silica and synthetic calcium aluminate). The proposed performance indicator (relative standardized leached calcium) allowed the materials to be classified according to their resistance to biogenic acid attack in sewer conditions. The repeatability of the test was confirmed using three different specimens of the same material within the same experiment and the reproducibility of the results was demonstrated by standardizing the results using a reference material from 5 different test campaigns. Furthermore, developing post-testing processing and calculation methods constituted a first step toward a standardized test protocol.


2003 ◽  
Vol 1832 (1) ◽  
pp. 191-200 ◽  
Author(s):  
Jonathan S. Gould ◽  
Yamini V. Nanagiri ◽  
Rajib B. Mallick ◽  
Joseph D. Petruccelli ◽  
William C. Crockford

The objectives of this research were to evaluate the rapid triaxial test method for use in quality control of hot-mix asphalt production and, if possible, determine test conditions for reliable results. The scope of this study consisted of testing different mixes at two different temperatures and frequencies and evaluating the results. The equipment was rugged and portable, and the hardware and software were easy to handle and did not require extensive technician training. The results from this study show that modulus and phase angle values obtained from testing are sensitive to key mixture components and properties. The coefficients of variation of results obtained from tests conducted at 60°C and 1 Hz are low. Tests with fine-graded mixes showed good correlation of dynamic stiffness parameters with rutting, and the stiffness parameters were found to be sensitive to the ratio of dust to effective binder. One significant advantage of using this test procedure as a regular quality control tool is that decisions can be made on the basis of performance-related parameters rather than on the basis of volumetric properties only. In view of its desirable qualities, this test method seems to be usable on a regular basis for quality control testing. However, before it is used, agencies must adopt a test protocol and establish target values and allowable variations.


1990 ◽  
Vol 36 (5) ◽  
pp. 792-797 ◽  
Author(s):  
H Paxton ◽  
T Bendele ◽  
L O'Connor ◽  
D C Haynes

Abstract The "LipoGen RheumaStrip ANA Profile" test method (LipoGen, Inc.) is a new assay format for autoantibody detection in which recombinant autoantigens are used. This enzyme immunoassay, in test-strip format, detects antibodies to autoantigens U1-ribonucleoprotein (U1-RNP), Sm, SS-A/Ro, SS-B/La, and to native DNA (nDNA). We evaluated 200 antinuclear antibody (ANA)-positive and 100 ANA-negative sera for the presence of antibodies to U1-RNP, Sm, SS-A/Ro, SS-B/La, and nDNA by the new test-strip procedure. These data correlated well with those obtained with either Ouchterlony double immunodiffusion for U1-RNP, Sm, SS-A/Ro, and SS-B/La or with Crithidia luciliae indirect immunofluorescence for anti-nDNA. Assay sensitivity and assay specificity of the ANA Profile method as compared with those of established procedures were respectively as follows: 89.8% and 98.8% for U1-RNP, 86.4% and 95.3% for Sm, 97.9% and 89.3% for SS-A/Ro, 98.3% and 86.3% for SS-B/La, and 97.5% and 93.1% for nDNA. Agreement between the ANA Profile test and these other test methodologies ranged from 88.7% for the SS-B/La test to 97.3% for the U1-RNP test. This new test procedure substantially decreases the time and effort required to perform these assays. Total hands-on time and overall assay time were decreased by 72% and 97%, respectively.


Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1018
Author(s):  
Johannes Haufe ◽  
Anya Vollpracht ◽  
Thomas Matschei

The European standard EN 206-1 contains descriptive requirements for concrete to withstand sulfate attack in the field. This approach limits the use of feasible concrete mixtures that don’t comply with these requirements. A performance approach based on the residual tensile strength of concrete briquet specimen according to ASTM C307 after storage in sodium sulfate solution close to field conditions is suggested by the authors. The newly developed test method is verified on a variety of 23 binders. Threshold values for the determination of the sulfate resistance of concrete after nine months of storage in 6000 mg SO42−/L sulfate solution at 5 °C are proposed. A first repeatability test as well as thermodynamic calculations prove the suitability of the method to test the performance of concrete during sulfate attack under practical conditions.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Rogério Lavanholi ◽  
Fabricio C. Oliveira ◽  
Antonio P. de Camargo ◽  
José A. Frizzone ◽  
Bruno Molle ◽  
...  

Emitter clogging is a major problem in microirrigation systems, which may result from the isolated or combined effects of physical, chemical, and biological agents. Clogging caused by suspended solid particles is the most common plugging form of emitters. Water quality and emitter geometry are key aspects in clogging processes. Any suitable test procedure to assess the sensitivity of drippers to clogging should take into account the predominant factors that influence clogging and must reproduce the field conditions. This research set out to assess the performance and suitability of a laboratory clogging test procedure in order to validate a methodology and to provide scientific results that may support the standardization of a clogging test method. The evaluated methodology has been used by the IRSTEA laboratory since 1974 (Platform of Research and experiment on Science and Technology for Irrigation - PReSTI, formerly LERMI) and its contents are currently being discussed by the ISO TC23/SC18 committee. The aim is to define a standardized testing protocol to evaluate the sensitivity of emitters to clogging due to solid particles. Replications analyzing the clogging resistance of four models of emitting pipes were carried out in a laboratory. The clogging test procedure enabled an accurate assessment of the combinations of concentration and size of particles that caused clogging in each model of dripper. However, a significant variability in degree of clogging was identified when the results of replications for each model of dripper were compared. Several requirements, concerns, and improvements related to the clogging test protocol were discussed.


1985 ◽  
Vol 22 (4) ◽  
pp. 592-599
Author(s):  
R. G. Horvath

A multiple loading testing method is suggested, which permits testing a single drilled pier foundation under three different conditions of load support. The pier may be tested under conditions of combined shaft and end-bearing resistance, end-bearing resistance only, and shaft resistance only. The advantages of this multiple loading test method include observation of the load-transfer and displacement behaviours of the pier under these three different support conditions and verification of the values obtained for the components of load support, i.e., shaft and end-bearing resistance, all from a single test pier.A special base load cell capable of performing a different function during each cycle of loading is required. A suitable load cell, consisting of a series of Freyssi flatjacks, and the method of operation are described.A multiple loading test procedure was used successfully as part of a field investigation program on full-scale pier sockets in weak shale. Data on the load-displacement behaviour of the pier tested using the multiple loading method are reported. Information concerning piers tested using conventional single loading methods are provided for comparison.The multiple loading test results were in good agreement with results obtained from conventional testing methods. Thus the multiple loading test method provides an economical means of obtaining a large amount of design information for drilled pier foundation systems, using a single test pier. Key words: field load test, multiple loading, drilled piers and caissons, shaft resistance, end-bearing resistance, combined shaft and end-bearing resistances, base load cell, shale.


2021 ◽  
Vol 8 (1) ◽  
pp. 59-64
Author(s):  
Almuzakkir . ◽  
Muhammad . ◽  
Adi Setiawan

Fuel is something that is very important in everyday life. Almost every human being needs fuel to meet their needs and support their activities, for example cooking in household needs. Currently, fossil fuels or fuel oil (BBM) are still widely used to meet demand, however, it should be noted that fossil fuels or fuel oil (BBM) are non-renewable natural resources. The biomass rocket stove is one of the modern stove innovations that uses biomass energy as the main energy source. Rocket stoves are designed to increase fuel efficiency with thermal efficiency, a combination of the increased combustion efficiency and heat transfer associated with burning briquette fuel. The purpose of this research is to design and manufacture rocket stove fired with coconut and bamboo biomass for household needs as well as developing methods and equipment for performance testing of rocket stoves. In this study, several steps were carried out, including designing a rocket furnace, selecting biomass fuel and testing the performance of a rocket furnace. From the design of the biomass stove, it is noteworthy that the design with two holes makes the combustion air easily enters and makes combustion in the furnace more perfect and efficient. Water boiling test using three types of solid fuels with the cold start condition suggested that the highest thermal efficiency was coconut fronds with a value of 38% and the lowest thermal efficiency was found from coconut shell combustion, i.e. 22%. During hot start test, the highest thermal efficiency was obtained from coconut fronds firing with a value of 41%. Moreover, with simmer water boiling test method, firing the rocket stove with coconut fronds showed the highest thermal efficiency with a value of 37%. Keywords: Rocket Stoves, Coconut Fronds and Shells, Bamboo, Thermal Efficiency, .Water Boiling Tests.


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