This study proposes a method for implementing distributed temperature sensing systems in tunnel fire simulations. A review of the investigations was conducted, and previous research on linear heat detection was examined. The characteristics and operational parameters of a complete DTS-based LHD system in a road tunnel are presented. A heat transfer model of the DTS sensor cable for CFD modelling was developed based on experiments in the standardised EN 54-5 wind tunnel for testing heat sensors. Based on the data analysis, substitute physical properties of the sensor cable were selected for the heat transfer model to allow implementation of the DTS model in CFD. Concurrently, an RTI value of 90 (m/s)(1/2) was approximated to compare the model with the response-time model commonly used in fire engineering analyses. To validate the model, two full-scale fire tests were carried out in a road tunnel in Swinoujscie, Poland, and CFD numerical simulations were performed with the proposed DTS model. The relative error of detection time prediction was within 3% for the case with low velocity, and successfully predicted no detection in the case with high velocity (>1 m/s). The developed model allows to tracking temperature changes of the DTS sensor cable with satisfactory precision and can be applied in various tunnel fire analyses.
In this study, we examined the evaluation method and evaluation criteria for evaluating the carbonation suppression effect of finishing materials used for the exterior of reinforced concrete buildings. We proposed a test method for carbon dioxide transmission rate of finishing materials and clarified the relationship with the carbonation ratio by the accelerated carbonation test while 52 weeks. In addition, the value of the carbonation ratio by previous studies, we proposed a criteria for the carbonation suppression effect in consideration of the deterioration of the finishing material.
This study investigates the applicability of non-contact 3D optical scanning for quantitative evaluation of abrasion damage in concrete floors and its consistency with the standard British Cement Association (BCA) abrasion test. Abrasion experiments were conducted under in situ conditions in accordance with the standard BCA abrasion test procedure, while surface wear was independently measured using a handheld metrology-grade 3D scanner supported by photogrammetric positioning and high-resolution local scanning. The acquired point cloud data were converted into triangular surface meshes and analysed using a mesh-to-mesh comparison approach, enabling spatially resolved assessment of abrasion depth. Fifteen measurement scenarios were examined to evaluate the influence of sampling density, point location strategy, and measurement technique. Statistical analysis based on the Shapiro–Wilk test and one-way ANOVA demonstrated that the observed variability of abrasion depth is governed primarily by heterogeneous surface damage rather than by the applied measurement method. The results show that 3D optical scanning provides abrasion-depth values consistent with conventional point-based measurements and does not affect abrasion-based material classification. Rather than replacing the standardized BCA procedure, the proposed approach complements its measurement stage by providing full-field geometric information that enables qualitative assessment of abrasion morphology, spatial variability and surface topography, thereby significantly enhancing the diagnostic capabilities of the test.
Celem artykułu jest ilościowa ocena przenikania włókien azbestu z zewnętrznych źródeł do wnętrza, na podstawie bilansu zmian liczby włókien w powietrzu zewnętrznym i wewnętrznym. Porównano, zanieczyszczenie powietrza wewnętrznego budynku z elewacją z płyt azbestowo-cementowych podczas: normalnej, bez destrukcyjnej eksploatacji poprzedzającej jej demontaż i w trakcie. Budynek był w ciągłym użytkowaniu. Oznaczenie koncentracji włókien azbestu prowadzono z użyciem mikroskopii optycznej kontrastu fazowego i polaryzacji światła oraz mikroskopii skaningowej SEM-EDS. Wynik badań określający transmisję włókien do wnętrza obiektu przedstawiono graficznie w formie trendów zmian koncentracji włókien azbestu w różnych etapach demontażu w pomieszczeniach nieużytkowanych i użytkowanych. Stwierdzono istotny wpływ emisji powstałej przy elewacji na powietrze wewnętrzne budynku. Powszechnie stosowane procedury izolowania budynku ograniczone do zamknięcia okien i uszczelnieniu ich taśmą są nieskuteczne w pomieszczeniach z aktywną wentylacją. W analizie zmian stężeń i ich interpretacji wykorzystano AI.
Assessment of fire resistance of masonry walls in engineering practice is most often based on tabulated data provided by Eurocode 6. The second generation of the standard significantly reduces the required wall thickness for achieving a given fire resistance rating, which raises doubts about its validity. This paper presents results from 15 full-scale fire resistance tests conducted over the past 20 years on loadbearing and non-loadbearing walls built with dense aggregate hollow and solid concrete blocks, joined with general-purpose cement mortar and left without surface finish. None of the hollow block walls achieved the ratings assigned by Eurocode 6, and several loadbearing walls at full utilisation collapsed much earlier than prescribed. One wall with concrete-filled voids and another with solid blocks demonstrated exceptional performance, sustaining over 4 h of fire exposure. numerical heat transfer analysis, using conservative material assumptions, confirmed the occurrence of high unexposed-side temperatures and highlighted the unrealistic nature of the new Eurocode values. The complete dataset is reported for reference, comparison, and reuse, with findings emphasising the influence of block geometry and void filling on fire resistance and the need to re-examine the simplified approach of the new standard.
