The mini-slump test is a fast, inexpensive and widely adopted method for evaluating the workability of fresh cementitious pastes. However, this method lacks a standardised procedure for its experimental implementation, which is crucial to guarantee reproducibility and reliability of the test results. This study investigates and proposes a guideline procedure for mini-slump testing, focusing on the influence of key experimental (mixing and testing) parameters on the statistical performance of the results. The importance of preparation of always testing at the same time after mixing, testing each batch once rather than conducting multiple tests on a single batch of material, is highlighted. A set of alkali-activated fly ash-slag pastes, spanning from 1 to 75 Pa yield stresses, were used to validate the test method, by comparison of calculated yield stresses with the results obtained using a conventional vane viscometer. The proposed experimental procedure for mini-slump testing produces highly reproducible results, and the yield stress calculated from mini-slump values correlate very well with those measured by viscometer, in the case of fresh paste of pure shear flow. Mini-slump testing is a reliable method that can be utilised for the assessment of workability of cements.
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http://dx.doi.org/10.1617/s11527-017-1103-x | DOI Listing |
Materials (Basel)
November 2024
Academic Department of Civil Construction (DACOC), Technological Federal University of Paraná (UTFPR), Curitiba 81280-340, PR, Brazil.
This manuscript evaluated the performance of silanes in cementitious matrices in the partial replacement of superplasticizers by silanes. For this, pastes with a water/cement ratio of 0.186 were produced and the superplasticizer admixture based on polycarboxylate esters was partially substituted by three types of silanes-vinyltriethoxysilane silanes (VTES), n-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AEAPTMS), and methacryloxypropyltrimethox-ysilane (MCPTMS)-in two substitutions levels (20% and 40%), and then tested in Portland cement pastes.
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October 2024
R&D Team, Newjust Co., Ltd., Gwangmyeong 14348, Republic of Korea.
This study aims to investigate the comparative performance of ester- and ether-based polycarboxylate superplasticizers in maintaining the fluidity and controlling the setting time of alkali-activated slag (AAS) paste. The experiments employed rheological tests, mini-slump tests, ultrasonic pulse velocity (UPV) measurements, and gel permeation chromatography (GPC) analysis. The results indicate that ether-based superplasticizers maintain fluidity approximately 25% longer than their ester-based counterparts and extend the setting time by about 30%.
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May 2024
Institute of Construction and Building Materials, Technische Universität Darmstadt, 64287 Darmstadt, Germany.
Low-grade limestone (LGL) is not used to produce cement clinker, but this leftover material in cement quarries increases the water demand when used as a filler in concrete production. In this study, the effect of six commercial superplasticizers on the performance of cement mixes containing 35% LGL and 2% gypsum was investigated. The optimal doses of these superplasticizers were found in a range of different water/binder (w/b) ratios by conducting several Marsh cone and mini-slump tests.
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June 2023
CONSTRUCT-LABEST, Faculty of Engineering (FEUP), University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal.
The workability of cement-based materials is one of the features that makes these construction materials the most used worldwide. Measuring and understanding how cement-based constituent materials affect fresh properties depends on the experimental plans. The experimental plans deal with the constituent materials used, the tests carried out, and the run of experiments.
View Article and Find Full Text PDFMaterials (Basel)
November 2022
Institute of Natural Resources, Unifei-Federal University of Itajubá, Av. BPS, 1303, Itajubá Cep 37500 903, MG, Brazil.
The addition of Superabsorbent Polymer (SAP) decreases the effect of autogenous shrinkage present in pastes, mortars, and concretes. In this study we investigated the influence of the addition of SAP in self-compacting cement paste mixtures. Eighteen 5 × 10 cylindrical specimens were molded in all, three for each mixture (CPII base, CPII 0.
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