Report of RILEM TC 267-TRM phase 2: optimization and testing of the robustness of the R3 reactivity tests for supplementary cementitious materials

Abstract

The results of phase 1 of an interlaboratory test, coordinated by the RILEM TC 267-TRM “Tests for Reactivity of Supplementary Cementitious Materials” showed that the R3 (rapid, relevant, reliable) test method, by measurement of heat release or bound water, provided the most reliable and relevant determination of the chemical reactivity of supplementary cementitious materials (SCMs), compared to other test methods. The phase 2 work, described in this paper aimed to improve the robustness of the test procedure and to develop precision statements for the consolidated test procedure. The effect of the pre-mixing and mixing conditions, and the impact of the mix design on the test method robustness were assessed and fixed for optimal conditions to carry out the R3 heat release test. The effect of the drying step was evaluated to define the R3 bound water test procedure in more detail. Finally, the robustness of the consolidated final test methods was determined by an interlaboratory study to define the precision statements.

Interlaboratory Test Program to Determine the Precision of the R3 Test Method (ASTM C1897-20) for Measuring Reactivity of Supplementary Cementitious Materials

“…The physico-chemical properties of the test materials are reported in Table 1 and Table 2 The test determinations were carried out on paste samples incorporating SCMs following the mix design of the model paste shown in Table 3. [10,12]. All paste constituents were weighed and brought to 40 °C before mixing.…”

“…In a first phase, existing and novel test methods were evaluated against robustness criteria and correlation to strength for conventional SCMs by round robin testing [5]. In a second stage, the test methods that performed best were investigated in more depth to further improve their performance and the description of the test procedures [6,7].As a result, the most promising test methods, i.e. the R3 test methods for heat release and bound water measurement, were recommended and presented to standardization committees.…”

“…The R3 test was adopted by ASTM as C1897 in 2020 [8].This interlaboratory study (ILS) was conducted by RILEM TC 267-TRM in line with ASTM C802 -14 [9] that provides guidelines to design, execution and analysis of the data with the objective of developing precision statements of the R3 test method (ASTM C1897-20) [8]. The precision statements provide acceptance values for the single-operator and multilaboratory standard deviations and difference limits expressed according to ASTM C670-15 [10].The ILS was preceded by a preliminary test program within RILEM TC 267 TRM to develop and refine the R3 test method [5,6,11] . The conduction of the preliminary test program involved all laboratories participating in the ILS, enabling them to get acquainted and receive training on the execution of the test method.…”

“…In a first phase, existing and novel test methods were evaluated against robustness criteria and correlation to strength for conventional SCMs by round robin testing [5]. In a second stage, the test methods that performed best were investigated in more depth to further improve their performance and the description of the test procedures [6,7].…”

“…The ILS was preceded by a preliminary test program within RILEM TC 267 TRM to develop and refine the R3 test method [5,6,11] . The conduction of the preliminary test program involved all laboratories participating in the ILS, enabling them to get acquainted and receive training on the execution of the test method.…”