While metadiscourse use has been well-attended in second language (L2) writing research, relatively less effort has been made in documenting changing patterns of metadiscourse use among L2 writers. The present study addressed this gap by probing a diachronic change of interactive metadiscourse in research articles published in English Teaching across a span of 40 years. Using the corpus of 931 articles written by Korean L2 writers, we examined whether, and to what extent, interactive metadiscourse use in academic writing had changed over time. Our findings revealed an overall increase in the frequency of interactive resources mainly driven by a significant increase of evidentials. The observed pattern of change in interactives suggests that academic discourse within the applied linguistics community in Korea is becoming more persuasive and reader-oriented over time, consistent with Hyland and Jiang (2018) who reported a dramatic rise in interactive metadiscourse in the global discourse community of applied linguistics.

While the use of metadiscourse in L2 writing has received considerable attention in the past, little effort has been made to examine how L2 writers’ use of metadiscourse in academic writing has evolved over time. In addressing this, the present study explored a diachronic evolution of interactional metadiscourse in research articles (RAs) published across a span of 40 years (1980-2021) in English Teaching. Based on 931 articles consisting of 6.4 million words, we examined whether the use of interactional metadiscourse has changed over the past 40 years. Our findings revealed that there was a global decrease in interactional metadiscourse over the past 40 years. While the frequency and diversity of interactional metadiscourse have slightly decreased over time, the proportion of each metadiscourse category remained consistent. The study further suggests that Korean L2 scholars who publish in English Teaching tend to hedge more than they boost or use attitude markers compared to those who publish in global journals.

PURPOSES : It is well known that low temperature cracking is one of the most serious distresses on asphalt pavement, especially for northern U.S. (including Alaska), Canada and the northern part of south Korea. The risk of thermal cracking can be numerically measured by estimating thermal stress of a given asphalt mixture. This thermal stress can be computed by low temperature creep testing. Currently, in-direct tensile (IDT) mixture creep test mentioned in AASHTO specification is used for measuring low temperature creep properties of a given asphalt mixture. However, IDT requires the use of expensive testing equipment for performing the sophisticated analysis process, however, very few laboratories utilize this equipment. In this paper, a new and simple performance test (SPT) method: bending beam rheometer (BBR) mixture creep testing equipment is introduced, and the estimated experimental results were compared with those of conventional IDT tests. METHODS: Three different asphalt mixtures containing reclaimed asphalt pavement (RAP) and roofing shingles were prepared in the Korea Expressway Corporation (KEC) research laboratory. Using the BBR and IDT, the low temperature creep stiffness data were measured and subsequently computed. Using a simple power-law function, the creep stiffness data were converted into relaxation modulus, and subsequently compared. Finally, thermal stress results were computed from relaxation modulus master curve using Gaussian quadrature approach with condierations of 24 Gauss number. RESULTS: In the case of the conventional asphalt mixture, similar trends were observed when the relaxation modulus and thermal stress results were compared. In the case of RAP and Shingle added mixtures, relatively different computation results were obtained. It can be estimated that different experimental surroundings and specimen sizes affected the results. CONCLUSIONS: It can be said that the BBR mixture creep test can be a more viable approach for measuring low temperature properties of asphalt mixture compared to expensive and complex IDT testing methods. However, more extensive research and analysis are required to further verify the feasibility of the BBR mixture creep test.