bluuebunny/crossref_metadata_2025 huggingface dataset:
The C-terminal domain of Hsp70 is responsible for paralog-specific regulation of ribonucleotide reductase
Authors: Knighton Laura E. , Nitika  , Omkar Siddhi , Truman Andrew W.
Published: April 2022

The Hsp70 family of molecular chaperones is well-conserved and expressed in all organisms. In budding yeast, cells express four highly similar cytosolic Hsp70s Ssa1, 2, 3 and 4 which arose from gene duplication. Ssa1 and 2 are constitutively expressed while Ssa3 and 4 are induced upon heat shock. Recent evidence suggests that despite their amino acid similarity, these Ssas have unique roles in the cell. Here we examine the relative importance of Ssa1-4 in the regulation of the enzyme ribonucleotide reductase (RNR). We demonstrate that cells expressing either Ssa3 or Ssa4 as their sole Ssa are compromised for their resistance to DNA damaging agents and activation of DNA damage response (DDR)-regulated transcription. In addition, we show that the steady state levels and stability of RNR small subunits Rnr2 and Rnr4 are reduced in Ssa3 or Ssa4-expressing cells, a result of decreased Ssa-RNR interaction. Interaction between the Hsp70 co-chaperone Ydj1 and RNR is correspondingly decreased in cells only expressing Ssa3 and 4. Through studies of Ssa2/4 domain swap chimeras, we determined that the C-terminal domain of Ssas are the source of this functional specificity. Taking together, our work suggests a distinct role for Ssa paralogs in regulating DNA replication mediated by C-terminus sequence variation.
Sex-specific distribution and classification of Wolbachia infections and mitochondrial DNA haplogroups in Aedes albopictus from the Indo-Pacific
Authors: Yang Qiong , Chung Jessica , Robinson Katie L. , Schmidt Thomas L. , Ross Perran A. , Liang Jiaxin , Hoffmann Ary A.
Published: April 2022

The arbovirus vectorAedes albopictus(Asian tiger mosquito) is common throughout the Indo-Pacific region, where most global dengue transmission occurs. We analysed population genomic data and tested for cryptic species in 160Ae.albopictussampled from 16 locations across this region. We found no evidence of crypticAe.albopictusbut found multiple intraspecific COI haplotypes partitioned into groups representing three Asian lineages: East Asia, Southeast Asia and Indonesia. Papua New Guinea (PNG), Vanuatu and Christmas Island shared recent coancestry, and Indonesia and Timor-Leste were likely invaded from East Asia. We used a machine learning trained on morphologically sexed samples to classify sexes using multiple genetic features and then characterized thewAlbA andwAlbBWolbachiainfections in 664 other samples. ThewAlbA andwAlbB infections as detected by qPCR showed markedly different patterns in the sexes. For females, most populations had a very high double infection incidence, with 67% being the lowest value (from Timor-Leste). For males, the incidence of double infections ranged from 100% (PNG) to 0% (Vanuatu). Only 6 females were infected solely by thewAlbA infection, while rare uninfected mosquitoes were found in both sexes. ThewAlbA andwAlbB densities varied significantly among populations. For mosquitoes from Torres Strait and Vietnam, thewAlbB density was similar in single-infected and superinfected (wAlbA andwAlbB) mosquitoes. There was a positive association betweenwAlbA andwAlbB infection densities in superinfectedAe.albopictus. Our findings provide no evidence of cryptic species ofAe.albopictusin the region and suggest site-specific factors influencing the incidence ofWolbachiainfections and their densities. We also demonstrate the usefulness of ddRAD tag depths as sex-specific mosquito markers. The results provide baseline data for the exploitation ofWolbachia-induced cytoplasmic incompatibility (CI) in dengue control.
Organic amendment plus inoculum drivers: Who drives more P nutrition for wheat plant fitness in small duration soil experiment
Authors: Ahmed Saba , Iqbal Nadeem , Tang Xiaoyan , Ahmad Rafiq , Irshad Muhammad , Irshad Usman
Published: April 2022

Functioning of ecosystems depends on the nutrient dynamics across trophic levels, largely mediated by microbial interactions in the soil food web. The present study investigated the use of phosphate solubilizing bacteria (PSB) and poultry manure (PM) for maintaining labile P in the soil for an extensive fertility enhancement and as a substitution of chemical fertilizers. Based on the different P solubilizing capabilities of Bacillus and Pseudomonas, a quadruple consortium of Bacillus subtilis, Bacillus cereus, Bacillus thuringiensis and Pseudomonas fluorescens, and their grazer nematodes (soil free living) supplemented with PM were studied. This study was carried out on the trophic levels of soil communities to assess the growth and availability of P to the wheat plants. Experiment was performed for 90 days. Comparing the unamended and amended predator results showed that nematode addition beyond bacterial treatment substantially increased the net available P by ≈2 times, and alkaline phosphatase (ALP) activity by 3.3 times. These results demonstrated the nematodes association with increasing nutrient availability or P mineralization. The interactive effect of PM as substrate and biological drivers was more noticeable on plant dry biomass (1.6 times) and plant P concentration (3.5times) compared to the similar unamended treatment. It is concluded that the biological drivers significantly enhanced the soil ALP and available P while the substrate and biological drivers enhanced dry biomass and plant P concentration. Bacterivore nematodes enhanced the effect of PSB for P mineralization via microbial loop and could be used for the enhancement of wheat production.
Long-term mortality of academy award winning actors and actresses
Authors: Redelmeier Donald A. , Singh Sheldon M.
Published: April 2022

Background

Social status gradients are powerful health determinants for individuals living in poverty. We tested whether winning an Academy award (Oscar) for acting was associated with long-term survival.

Methods

We conducted a longitudinal cohort analysis of all actors and actresses nominated for an Academy award in a leading or a supporting role. For each, a control was identified based on age, sex, and co-staring in the same film.

Results

Overall, 2,111 individuals were analyzed with 1,122 total deaths occurring during a median follow-up of 68.8 years. Comparisons of winners to controls yielded a 4.8% relative difference average life-span (95% confidence interval: 1.6 to 7.9, p = 0.004), a 5.1 year absolute increase in life expectancy (95% confidence interval: 3.0 to 7.2, p < 0.001), and a 41% improvement in mortality hazard (95% confidence interval: 19 to 68, p < 0.001). The increased survival tended to be greater in recent years, for individuals winning at a younger age, and among those with multiple wins. The increased survival replicated in secondary analyses comparing winners to nominees and was not observed in analyses comparing nominees to controls.

Conclusions

Academy award winning actors and actresses show a positive association between success and survival, suggesting the importance of behavioral, psychological, or other modifiable health factors unrelated to poverty.
Adaptive HIV pre-exposure prophylaxis adherence interventions for young South African women: Study protocol for a sequential multiple assignment randomized trial
Authors: Velloza Jennifer , Poovan Nicole , Ndlovu Nontokozo , Khoza Nomhle , Morton Jennifer F. , Omony Jeanne , Mkwanazi Edwin , Grabow Cole , Donnell Deborah , Munthali Richard , Baeten Jared M. , Hosek Sybil , Celum Connie , Delany-Moretlwe Sinead
Published: April 2022

Introduction

Pre-exposure prophylaxis (PrEP) is a highly effective HIV prevention strategy and is recommended for populations at risk of HIV, including adolescent girls and young women (AGYW) in HIV endemic settings. However, PrEP continuation and high adherence remain challenges to its impact. Existing PrEP adherence interventions can be time- and cost-intensive. Widescale PrEP delivery will require the identification of layered PrEP support strategies for AGYW with diverse prevention needs. We describe the design of a sequential multiple assignment randomized trial (SMART) to evaluate a PrEP adherence support model using scalable, stepped interventions in AGYW in South Africa.

Methods

“PrEP SMART” is a randomized trial in Johannesburg, South Africa, enrolling AGYW who are between 18 and 25 years of age, sexually active, newly initiating PrEP, and have regular access to a mobile phone. Participants are randomized 1:1 to standard-of-care PrEP counseling with either two-way SMS or WhatsApp group adherence support. Adherence is assessed at three months using tenofovir diphosphate (TFV-DP) levels from dried blood spots collected at month 2 to categorize participants as “responders” (TFV-DP ≥500 fmol/punch) or “non-responders” (TFV-DP <500 fmol/punch). AGYW defined as ‘non-responders’ undergo a secondary 1:1 randomization to either quarterly drug-level feedback counseling or monthly issue-focused counseling, in addition to their first-level intervention. The primary outcome is PrEP adherence at nine months (TFV-DP ≥700 fmol/punch). We will assess the effect of our two initial interventions on TFV-DP levels among responders, assess the effect of our intensified interventions on TFV-DP levels among non-responders, and identify the optimal sequence of adherence interventions through nine months.

Trial registration

ClinicalTrials.gov, NCT04038060. Registered on 30 July 2019.
Karyotype and genome size in Adonis vernalis and Adonis volgensis
Authors: Mitrenina Elizaveta Yu. , Erst Andrey S. , Skaptsov Michail V. , Smirnov Sergey V. , Zolotov Dmitry V. , Leonova Tatyana V. , Tashev Alexander N. , Bancheva Svetlana T. , Wang Vey
Published: April 2022

The comparative karyological analysis of Adonis vernalis and Adonis volgensis (Ranunculaceae) from 11 populations from Russia (Altai Territory, Novosibirsk Region, Republic of Khakassia) and Bulgaria was carried out. The somatic chromosome number was 2n = 16 in all studied plants. Chromosome sets of A. vernalis from the Altai Territory (near Sibirskiye Ogni village) and the Republic of Khakassia (Tashtipskiy District), A. volgensis from the Altai Territory (near Chernopyatovo village) and Bulgaria (Kavarna Municipality) consist of eight metacentric and eight submetacentric chromosomes. Two pairs of submetacentric chromosomes had small satellites in short arms. The karyotype formula of these plants was 2n = 2x = 16 = 8m + 4sm + 4smsat. The specimen with the chromosome rearrangement (nonreciprocal translocation) was found in the Altai Territory population. The chromosome mutation has changed the chromosome morphology of submetacentric pair to metacentric pair of different size. The karyotype formula of this specimen was 2n = 2x = 16 = 2n = 10m + 6sm. A similar mutation was previously found out in A. apennina (A. sibirica) from the Tomsk Region. The nuclear DNA content (2C-value) was determined in eight Adonis populations by flow cytometry. The average absolute nuclear DNA content in A. vernalis attained on from 18.88 ± 1.01 to 19.47 ± 1.17 pg, and in A. volgensis attained on from 16.10 ± 0.41 to 16.47 ± 0.47 pg. Differences in 2C-value between A. volgensis and A. vernalis correlated with differences in total chromosome lengths of the set.
Floristic findings in the Republic of Tuva and in the south of the Krasnoyarsk Territory (Upper Yenisei basin)
Authors: Shaulo Dmitry N. , Zykova Elena Yu. , Shmakov Alexander I. , Tupitsyna Natalya N. , Artemov Igor A. , Sonnikova Alexandra E. , Sambuu Anna D. , Erst Andrey S. , Karakulov Anatoliy
Published: April 2022

In the course of field research, analysis of previously published works and review of materials stored in well-known collection funds of Siberia (NS, KRAS, SSHZ), information on the distribution of rare adventitious and native plant species in the Upper Yenisei basin was clarified. For the first time, Arctium lappa, Armoracia sisymbrioides, Bupleurum sibiricum, Calystegia sepium, Lolium perenne, Pastinaca sativa, and Polygonum subaphyllum were noted for the flora of the Republic of Tuva. Stipa glareosa was collected for the first time on the territory of the Krasnoyarsk Territory. Viola tricolor was turned out to be new for the flora of the Sayano-Shushensky Reserve. For 10 rare species, new locations were noted and range boundaries were specified: Acer tataricum, Armoracia rusticana, Avena fatua, Carduus nutans, Clematis aethusifolia, Convolvulus arvensis, Polygonum rurivagum, Sedum acre, Setaria pumila, and Viola tricolor.
Overview of taxonomic relationships in the Allium sewerzowii (Alliaceae) affinity group
Authors: Krasovskaya Lyudmila S. , Levichev Igor G.
Published: April 2022

The history of the study and a critical review of taxonomic independence of eight narrow endemics of the Western Tien Shan from the Allium sewerzowii Regel (Alliaceae) kinship group are presented. Taxonomically significant features determining the species status of members of this group are characterized and illustrated. Based on morphological and geographical analysis correlated with molecular data, the species independence of A. motorKamelin et Levichev was confirmed. The authorship of the name A. tschimganicum B. Fedtsch. ex Vved. has been clarified. The key for identification of the species of this group from the section Acmopetala R. M. Fritsch is given. The applied value of the A. motor is qualified as a “springtime food stimulant”, toning the human nervous system.
To the knowledge of xerophytic floras of the Earth
Authors: Kamelin Rudolf V.
Published: April 2022

A review of both classes of flowering plants in the system of A. L. Takhtajan (1987) showed a general picture of the distribution of xerophytic phyla and groups in the Earth floras. The xerophilic lines of development in flowering plants are very ancient, and there are more of them among dicots than monocots. Xerophytic groups are more diverse in the floras of the Southern (compared to the Northern) Hemisphere, where the main centers of development of xerophilic floras are in South America, South Africa, and Australia. At the same time, New World xerophilic floras differ from Old World ones in the presence of a larger number of endemic families. The xerophytic centers of the Northern Hemisphere are in the tropics and subtropics, both in the Old and New Worlds: Africa, Arabia, India, the Mediterranean, North America (Madrean sub-kingdom).
Revision of the genus Calamagrostis Adans. in Altai Territory
Authors: Zolotov Dmitry V. , Ryzhakova Dar'ya D. , Kryuchkova Elizaveta A. , Gudkova Polina D.
Published: April 2022

Based on the revision of the grass collections kept in the herbaria of ALTB, KUZ and the Tigireksky State Nature Reserve, the composition of the Calamagrostis genus in the Altai Territory was clarified. In total, 12 species and 2 notospecies of the genus are given for the region. Two new notospecies of Calamagrostis were found for Altai Territory (C. × andrejewii, C. × thyrsoidea), of which both are new records for the Western Siberia, the latter is new for Siberia as well. In addition, an original key has been compiled to identify the representatives of the Calamagrostisgenus, taking into account new information and photos of diagnostic characters. Also, the distribution and ecology of species and notospecies of the genus Calamagrostis in the Altai Territory are specified.
New and rare species in the Kuzbass flora
Authors: Sheremetova Svetlana A. , Khrustaleva Irina A. , Ebel Alexander L. , Kupriyanov Andrey N. , Andreev Boris G. , Strelnikova Tatyana O. , Ebel Tatyana V. , Gudkova Polina D.
Published: April 2022

Data on findings of new and rare species in the Kemerovo Region are given. For the first time for the territory of Siberia as a naturalized species Trifolium pannonicum is indicated. Another species listed for the first time for the Altai-Sayan region is Linum catharticum. 14 new species and 2 interspecific hybrids are listed for the Kemerovo Region: Adenophora lamarckii, Astragalus macroceras, Cardaria draba, Chrysaspis campestris, Galium aparine, Genista tinctoria, Geranium sergievskajae, Hypericum attenuatum, Juncus nastanthus, Oxytropis intermedia, Poa insignis, Poa × intricata, Poa sergievskajae, Potamogeton × angustifolius, Stipa krylovii, Trapa natans. New locations have been recorded for 21 species that are rare in the Kuzbass: Aconogonon divaricatum, Agropyron pectinatum, Amaranthus blitoides, Astragalus vaginatus, Chaenorhinum minus, Dactylorhiza viridis, Dianthus deltoides, Dracocephalum krylovii, Echinops sphaerocephalus, Elodea canadensis, Elymus excelsus, Geranium laetum, Hypericum maculatum, Juglans mandshurica, Juncus vvedenskyi, Leymus paboanus, Rubus humulifolius, Stellaria cherleriae, Sanicula europaea, Suaeda prostrata, Woodsia calcarea. Of the 18 new taxa for the Kemerovo Region, 6 species are adventive.
Using an analysis of concrete and cement EPD: verification, selection, assessment, benchmarking and target setting
Authors: Anderson Jane , Moncaster Alice
Published: April 2022

The carbon embodied in buildings is an important proportion of our emissions and needs to be radically reduced in order to support climate change mitigation. The highest proportion of embodied carbon is usually emitted during the product stage, and within the structural elements. Therefore, reducing the carbon embodied in the structural materials is likely to have a major impact. In most buildings, the majority of embodied carbon comes from steel and concrete. But although there are now hundreds of registered Environmental Product Declarations (EPD) for cements and concretes, there has been very limited independent published information comparing the embodied carbon of different concrete mixes and raw materials. This lack of comparative data limits the potential to make appropriate decisions at early design stages leading to low carbon buildings.
The authors have recently conducted a review of verified EPD for concrete mixes and for concrete’s key constituents, including cement, identifying the range of carbon coefficients. This paper provides guidance on making use of the coefficient ranges provided in that research: to support the verification of EPD for concrete and its raw materials; in material selection; in assessing building level embodied carbon; in benchmarking; and in the setting of reduction targets.
Stainless steel-FRCM system for strengthening of RC beams: towards a sustainable strengthening technique
Authors: Bencardino Francesco , Nisticò Mattia
Published: April 2022

Fabric-Reinforced Cementitious Matrix (FRCM) systems for strengthening concrete structures are an alternative to traditional techniques. The FRCM system is a composite material consisting of two or more layers of cement-based matrix reinforced with dry fibres in the form of open mesh or fabric. When adhered to concrete structural members the FRCM system acts as supplemental external reinforcement. Many existing Reinforced Concrete (RC) members exhibit degradation due to the carbonation of concrete and/or corrosion of internal reinforcing steel bars. These RC members can be strengthened using stainless steel, in strip format (unidirectional fibres), embedded in a cementitious based matrix. The system, named Stainless Steel-FRCM, can be applied according to the Externally Bonded (EB) technique. In order to reduce times and costs of intervention, number of used materials, as well as the amount of chemical compounds, a novel Inhibiting-Repairing-Strengthening (IRS) technique is proposed and experimentally tested. Using a suitable matrix (thixotropic mortar with passivation properties) the main three operations of steel bars corrosion  inhibition/protection, restoring of deteriorated concrete, and installation of the external strengthening can be carried out in one-step. For evaluating the effectiveness of both new strengthening system and installation technique an extensive experimental investigation was planned and developed. A part of the experimental research includes two groups of three RC beams (3.00 m and 4.80 m long): one strengthened withIRS technique, one strengthened with EB technique and one control beam. These beams were tested  under monotonic loading. Further two beams, one beam for each group, strengthened according to IRS technique, were also tested under cyclic loading. The experimental results show the validity of the proposed solution in terms of structural performance and environmental sustainability.
Durability of GFRP connectors under sustained compression load for use in sandwich walls
Authors: Carstens Stefan , Pahn Matthias
Published: April 2022

Precast concrete sandwich panels are used to fulfil the rising thermal requirements. The sandwich walls consist of three layers, a facing, a thermal insulation layer, and a load bearing layer. The two outer layers are coupled by connectors made of glass-fibre reinforced polymer. A lack of knowledge about load-bearing behaviour prevents the removal of sustained compressive loads. In the context of this article, tests under sustained compressive load are presented. To represent closely the in service-conditions of sandwich walls, the examined connectors were subjected to a saturated alkaline concrete environment as well as to a specified stress level till failure occurs. Thus, the experimental setup combines alkaline resistance and creep rupture tests into one comprehensive testing. By using temperature effects as an accelerating factor, reasonable test durations were enabled. The obtained time to failure line was determined to extrapolate the characteristic values of the long-term strength for a service life up to 50 years. The test results are compared and evaluated with existing test results under a sustained tensile load.
Feasibility experiments of seismic concrete block walls without joint mortar
Authors: Choi Ho , Jin Kiwoong , Jeong Jaecheon , Kim Bongseok , Hwang Eonju
Published: April 2022

The authors developed two types of block systems consisting only of main block and key block without joint mortar in consideration of seismic performance and workability. Two types of block systems have different key block shapes: One is the peanuts shape and the other is the dumbbell shape. In this study, the proposed two types of block walls as well as a typical block wall were experimentally investigated to evaluate the seismic performance. In the tests, full-scale, single-story specimens were tested under static cyclic in-plane loading, and failure patterns and cracks were carefully observed. In this paper, the loading bearing capacity, energy dissipation capacity and reuse ratio of block walls are discussed in detail. As a result, the deformability, energy absorption capacity and reuse ratio of the proposed block systems were considerably higher than those of typical block system.
Strength and durability characteristics of self compacting concrete (SCC) with recycled aggregate and manufactured sand
Authors: Chundupalle Sashidhar , Seeri Nirmala , Veera Sudarsana Reddy , Nelluri Venkata Ramana
Published: April 2022

The investigations on self compacting concrete (SCC) with recycled coarse aggregate and Manufactured sand (M-Sand) were performed in this current study. The SCC mixtures were produced with the recycled coarse aggregate of proportions of 0 to 100% with step increment of 25% with a ratio of water binder at 0.36. In addition, the mixtures were also prepared by mixing it with M-Sand. The feasibility of utilizing the recycled coarse aggregate in SCC was evaluated through strength an  durability studies. The obtained results demonstrated that the SCC produced from these materials can be effectively recommended for their usages in concrete industries.
Limitations of life cycle assessment of green concretes - a state-of-the-art review
Authors: Dacić Amina , Fenyvesi Oliver
Published: April 2022

There have been numerous researches focusing on the alternatives to conventional concrete regarding environmental benefits and trade-offs. For this purpose, nowadays, the Life Cycle Assessment (LCA) is widely used. Until now, LCA results of conventional and green concretes have shown some limitations, and this paper focuses on addressing them. Firstly, the researches have been mostly based on a small number of concretes, which can limit the possibility to quantify the range of emissions for different set of assumptions. The second one is regarding the appropriate selection of functional unit where a divergence between different researches is visible. Moreover, it has been recognised that the criteria involved in the investigation of transportation might lead to the variation of results. Also, inventory allocation has to be assessed in detail to reach adequate distribution of the environmental impact of the concrete during its life cycle phases. Finally, CO2 uptake of the concretes throughout the life cycle should be considered and applied adequately to have representative results of overall CO2 emissions. It is expected that the differences will depend on construction practices among the countries where the researches are executed. Also, the results will surely vary between different system definitions when LCA is applied.
Analyzing the impact of the aspect ratio of a building on concrete use in its structure
Authors: Dixit Manish K. , Pradeep Kumar Pranav
Published: April 2022

Buildings consume over half of annual energy supply as embodied and operating energy in their construction and operation releasing harmful emissions to the atmosphere. Over 90 % of the embodied energy is attributed to construction materials used in building structure, envelope, and interiors that must be reduced to minimize material use. Concrete is one of the major materials that contributes significantly to the energy and carbon footprint of buildings, as it is responsible for 5-9 % of global carbon emission. Because most of the concrete use in the building sector occurs in building structures, assessing how building design parameters influence its environmental sustainability is important. One of the design parameters that impact the sustainability of buildings is the aspect ratio, which is defined as the ratio of horizontal to vertical surface area of a building. A building with the same floor area can be designed horizontally or vertically with different aspect ratios, which will influence its structural design and eventually the amount of concrete used in the building. In this paper, we examine how aspect ratio may affect the environmental sustainability of a buildings foundation, structural framing, and slab. We model the structure of a generic building with different aspect ratio to analyze if aspect ratio can help reduce the energy and carbon embodied in reinforced concrete structures.
Energy flows along the production and use of secondary materials with a special focus on concrete
Authors: Gruhler Karin , Schiller Georg
Published: April 2022

Urban mining in the existing building stock can contribute to securing raw materials and conserving natural resources if the potential of recycling construction waste is consistently exploited. From an ecological point of view, it is on the one hand interesting what amounts of primary materials can potentially be substituted and on the other how much energy need to be invested for this. At present, the recycling of construction waste usually is considered from a material perspective. There is lack of an approach, extending material-oriented considerations by energetic aspects. The aim is to develop a uniform research approach by which energy expenditure during recycling of important construction products can be determined. Besides concrete seven further construction products are  investigated. Recycling paths are described and analysed along waste management processing steps taking into account the quality of the demolition materials and the quality requirements of the possible new application variants in the construction sector. The result is a clear plea for more consistent recycling. The analyses of concrete indicate that "high-quality" recycling only results in energy advantages when "high-grade" demolition material is used. However, so-called "down-cycling" solutions allow resource conservation to be combined with energy savings, even with lower-quality demolition materials. The single-minded focus on "high-quality" recycling according to the general understanding should therefore be questioned. Instead, preference should be given to solutions that take resource conservation into account in a more holistic way especially with regard to resource conservation andclimate protection.
Tensile behavior of newly developed undercut anchor in cracked and uncracked concrete
Authors: Hatanaka Tomoyuki , Funaki Naoki , Tanaka Reiji , Fujita Shogo
Published: April 2022

The authors have been designing a post-installed anchor that fixes itself into concrete material by expanding the anchor tip in an upward direction, and conducted tensile loading tests to confirm its fundamental dynamic characteristics. The test results on three types of test specimens, with anchor morphology as a parameter, indicate that the final failure modes were all anchor bar fractures, and a stable yield strength was confirmed. Additionally, the yield strength characteristics of the proposed anchor in cases where cracks are present on the concrete surface, wherein the anchors are fixed, were experimentally confirmed.
Utilization of recycled and secondary materials in concrete production - LCA
Authors: Horáková Anna , Kohoutková Alena , Broukalová Iva
Published: April 2022

The paper describes an assessment of concrete in terms of environmental impacts in relation to the utilization of recycled materials. The article includes a short summary of the literature search on evaluation methods for environmental impacts and on recycled and secondary materials. The environmental impacts of several concrete mixtures were calculated. The reference concrete mixture containing only cement as a binder and only natural aggregate was compared with other mixtures containing recycled and secondary materials as a binder or aggregates. Some of these concrete mixtures were then compared within the whole structure. Variant design of a simple structure was performed, whereas the variants differed in the concrete mixture. These variants were then evaluated in terms of environmental impacts.
Stability of concrete containing blast-furnace slag following exposure to cyclic elevated temperature
Authors: Iravani Ahmad , Feldrappe Volkert , Ehrenberg Andreas , Anders Steffen
Published: April 2022

Concrete is widely used in constructions such as industrial floors or airducts in steel- and casting industry where it is often exposed to long-term or cyclic elevated temperatures. For these applications, thermal stability of concrete is of vital importance. The strength reduction dueto elevated temperatures depends on the temperature level and concrete composition. In this study, the effects of blast-furnace slag cement (CEM III/A) and basaltic aggregates were investigated at temperatures 250◦C to 700 ◦C in comparison to conventional Portland cement (CEM I) containing quarzitic aggregates. The concretes were cyclically exposed to high temperatures. Special attention was paid to mass loss, residual compressive and residual flexural strength depending on type of cement and aggregate as well as the number of thermal cycles. Mass loss and strength loss increased with increasing maximum temperature level, as expected. It was generally observed that concretes containing CEM III/A displayed significantly higher residual mechanical properties for almost all temperature levels. Concretes containing a combination of CEM III/Awith basaltic aggregates showed significantly higher stability at elevated temperatures compared to other concrete mixtures. It is further shown that apart from the maximum temperature the number of thermal cycles is important for the residual mechanical properties.
Optimizing the acid resistance of concrete with granulated blast-furnace slag
Authors: Kempf Luca-Alexander , Breitenbücher Rolf , Gerten Christian , Ehrenberg Andreas
Published: April 2022

Concrete structures exposed to high levels of chemical attacks are assigned to exposure class XA3, which recommends separate concrete protection or a special expert solution to ensure durability. Due to the partial substitution of Portland cement by blast-furnace slag, an increased resistance to acid attacks could be achieved within the framework of a research project. The technical and ecological advantages of cements containing granulated blast-furnace slag were exploited through chemical, granulometric and concrete technological optimizations. Despite extensive parameters, a statistical test design (DoE) was able to limit the experimental effort, thus defining principles for the conception of binder systems with increased chemical resistance.Mortar prisms indicated that the use of (ultrafine) blast-furnace slags (up to 13,000 cm2/g according to Blaine) with a broad particle size distribution can have a positive effect both on the capillary/gel pore ratio and on the calcium hydroxide content in the cement stone. Furthermore, the chemical composition of the blast-furnace slag as well as the water-binder ratio are decisive influencing factors for the acid-resistance, which was confirmed in accelerated acid resistance tests on concretes (pH-stat method). After 13 weeks of storing concrete specimens in sulfuric acid (H2SO4, pH 3.5), reduced damage depths and lower weight losses were observed compared to conventional binder compositions. The results serve as a basis for the development of highly acid-resistant concretes using blast-furnace slag-containing binder systems. Currently, the acid resistance of those concretes is being investigated in a long-term study by outsourcing representative test specimens into the Emscher sewer.
Suggestion of ultimate strength formulas of partial frame pile cap composed of exterior column, foundation beam and pile
Authors: Kishida Shinji , Mukai Tomohisa
Published: April 2022

Currently, there is no research and few valid experiments of pile caps. And shear failure mechanism of a pile, exterior column and foundation beam and pile caps in RC structure is not resolved yet under bi-lateral loading. Therefore, a performance evaluation method based on mechanical behaviour for pile caps has not been established. First, the fracture type was specified from the experimental results. Secondary, the ultimate strength formula of the pile cap was proposed based on the previous experimental results. It is a theoretical formula based on the truss-arch theory. It was confirmed that this formula can accurately evaluate the ultimate strength of the pile cap.
Comparing the environmental performances of new and renovated school buildings
Authors: Mancinelli Oscar , Fantilli Alessandro Pasquale , Chiaia Bernardino
Published: April 2022

Evaluating which is the best choice between renovating an existing construction or building a new structure in countries like Italy, where a huge post-war un-listed building heritage does not satisfy the current standards and the economic resources are limited, is not trivial. Several parameters come into play, such as such the extent of the construction work, the environmental cost of disposing old materials, the carbon footprint and volume of new materials. This paper is devoted to the analysis of two projects. The first consists of a renovation of a multi-storey existing school built in 1960s having total area of about 9900 m2. The second is a new construction of a three-story school having a total area of about 14000 m2 and made with timber. The results show that the existing school building, although having a lower embodied carbon related to materials, has a higher overall carbon footprint due to the CO2 emissions related to operational energy.
An experimental study of reinforced concrete beamcolumn joint with partially high strengthened longitudinal bar
Authors: Murata Yoshiyuki , Kitayama Kazuhiro , Kishida Shinji , Murakami Ken
Published: April 2022

It is necessary to generate the yield position away from the column face to minimize damage to the beam-column joint during a large earthquake in a reinforced concrete building. The same efficacy can be realized using partially high strengthened rebar. The number of longitudinal bars can be calculated for a bending moment smaller than the column face, reducing their number compared to the conventional bar-arrangement method. This paper describes reinforced concrete an interior beam-column subassemblage tests using this rebar as the longitudinal bars of beams and a column. The beam yield hinge was formed at a position apart from the column face, and the damage to the beam-column joint was less than the conventional bar-arrangement method. Additionally, the good performance was obtained if the bending strength of the column was large, even if the shear capacity margin of the beam-column joint was small. The column-beam flexural strength ratio and shear capacity margin at the beam-column joint need to be set with consideration of their relationship.
Analytical simulation on experimental seismic response of headed anchors embedded in reinforced concrete
Authors: Nagata Seiji , Matsuo Toyofumi , Morozumi Hironori , Ohtomo Keizo
Published: April 2022

This paper deal with a series of dynamic response analyses, carried out to give numerical correlation of hysteretic behavior of cast-in-place anchorages obtained by the static loading and shake table tests. Specimens for the analyses are reinforced concrete rectangular blocks with embedded headed anchors. Failure modes expected are the steel bolt failure and the concrete cone failure, associated with the respective embedment depth. Initial flexural cracks presumed seismic damage on the concrete block is developed with bending loading. In the analytical model, nonlinear hysteretic behavior of the anchorage is idealized by translational and rotational springs in which properties estimated from the hysteretic loops of the static loading tests. It was shown that the overall force and displacement performance under dynamic loads are well simulated based on the analytical models presented herein.
Physical properties of portland cement based concrete exposed at a depth of 3520 m in the Nankai Trough
Authors: Nomura Shun , Kasaya Takafumi , Sakoi Yuki , Fukada Hisashi , Matsumoto Akira
Published: April 2022

Concrete is widely used in large-scale construction of submarine infrastructure because of its high strength, durability, and ease of handling. However, knowledge of its durability in deep seawater is lacking. In the deep sea, materials are exposed to high pressures and low temperatures, which may cause early deterioration of concrete over time. Concrete materials may also be affected by the chemical composition of seawater, which induces the leaching of calcium. In situ exposure tests are therefore important for understanding degradation processes in the deep sea. In this study, Portland cement based concrete specimens were placed at a depth of 3520 m on the northern edge of the Nankai Trough in 2018 and retrieved in 2019, in the deepest exposure testing conducted to date. Here we provide an outline of the tests, describe the physical properties of materials exposed to deep seawater, freshwater, and air, and discuss possible concrete degradation mechanisms.
Research focused on low carbonation of concrete under old cement-based render
Authors: Paulík Peter , Gašpárek Jakub , Bačuvčík Michal , Janotka Ivan
Published: April 2022

In-situ research and laboratory study of the concrete of old bridges shows that despite the low strength classes of concrete and the long time of exposure to CO2, it is possible to moderate the depth of their carbonation. Many old bridges were found during the in-situ survey in Slovakia, which showed negligible carbonation under an old cement render (PRC) even after more than 100 years of direct exposure to CO2. At the same time, it was found that if this protective layer was significantly damaged or missing in some places, the depth of carbonation of the same concrete reached considerable depths, locally 70-80 mm. The article presents and summarizes the findings from in-situ and laboratory research with a possible explanation of this phenomenon.
Lateral load bearing characteristics of light gauge steel and lightweight concrete shear walls
Authors: Quan Chunri , Huang Qiang , Li Dongbin , Chen Yong
Published: April 2022

In China, there is a new structural system named light gauge steel and lightweight concrete (LSLC) structure, which used lightweight concrete as structural material in composite way with cold-formed steel. Here, the shear walls are the main structural members for the LSLC structure, which are assembled with the light gauge steel lattice columns and horizontal braces, and filled with lightweight concrete. In this study, the LSLC shear walls are experimentally investigated to evaluate their failure mechanism and lateral load bearing capacity. For this purpose, several specimens with different shear span ratio are designed and tested under static cyclic loading. This paper presents the damage state and hysteresis loops of the specimens detailly. Then, the lateral load bearing characteristics of the LSLC shear walls are discussed according to the failure mechanism, such as shear and flexural failure. Finally, the calculation methods of lateral strength for the LSLC shear walls are proposed based on the diagonal strut mechanism and sectional force equilibrium.
How design concepts influence carbon footprints of load bearing structures
Authors: Rønning Anne , Prestrud Kjersti , Saxegård Simon , Haave Simen S. , Lysberg Magne
Published: April 2022

In recent years, it has become essential to consider the total carbon footprint of a construction project. Commonly, the question has been: ’What is the best material to be used in this context?’ In this paper we argue that this question is incomplete, not taking the complexity of design choices into consideration. This paper intends to share light on how to analyse some factors that influence the construction of buildings in order to contribute to climate change mitigation, taking this complexity into consideration. Calculation of fossil greenhouse gas (GHG) emissions for two load-bearing structures for office buildings in 4, 8 and 16 storeys with equal functional requirements; e.g. load bearing capacity, acoustic performance, fire resistance and adaptability are addressed. The main materials for the load-bearing structures are cross laminated timber (CLT) elements and precast concrete elements respectively. The result show that one cannot on a general basis conclude that either type of load-bearing structure cause less fossil GHG emissions. It is always important to consider the building design, functionality as well as external conditions such as location when considering different load-bearing structure materials.
Methodology for evaluation of the life cycle of buildings with a focus on the private sector
Authors: Schneiderová Heralová Renáta , Hromada Eduard , Holcman Jakub , Vitásek Stanislav
Published: April 2022

The paper describes the innovative methodology for the evaluation of the life cycle of buildings, which will be used in construction projects of Skanska, or other construction companies, in selecting the optimal solution from the point of view of construction engineering and LCC. The aim is to help LCC to be perceived by construction practice as a topic that needs to be addressed at the beginning of each construction project. The quantification of life cycle costs based on relevant input data on the technical parameters of the construction, structural elements and equipment, the time period of incurring the related costs should be an important basis for the decision of the investor, designer and future user of the building also with regard to environmental and social aspects, and in particular the long-term economic consequences.
The status of sustainable concrete codes in the United States
Authors: Taylor Andrew Warren
Published: April 2022

As the focus on embodied carbon within the built environment has grown in the U.S., local jurisdictional codes have increasingly proposed and implemented code language that requires the use of concrete mixtures that have reduced environmental impacts. This paper provides details about the various ways that localized sustainable concrete provisions have been proposed and implemented in the U.S., including limits on cement content and Global Warming Potential (GWP). These laws and code revisions vary in their measurement of low-carbon concrete and their exemptions and incentives. While the current version of the ACI Building Code, ACI 318-19, does allow for the consideration of sustainability in concrete design, specifics about how the relative sustainability of concrete mixtures and systems are to be measured and compared are not included. This paper addresses how the changing landscape of local jurisdictional codes is driving the development of future ACI 318 provisions to play a part in providing more consistency in the application of sustainable design practices in the United States.
Rational and sustainable procedure in the design of bridges using pre-stressed concrete beams a theoretical practical method
Authors: Xochicale Cortés Abel Noé
Published: April 2022

Currently there is not a direct procedure for the design of this bridge system, the procedure is still based on trial and error, there are no studies that give us both the optimum number of beams and other characteristics such as the correct thickness of the slab or its adequate strength. Keeping in mind the concept of optimization, which supports the idea of sustainability and environmentally friendly structures, we apply this concept to the design of pre-stressed concrete girder bridges, which are an integral part of the road network in most countries of the world. Knowing also that concrete is the most produced material by man and that without it, it would be difficult to understand our current world, due to its own characteristics that make it unique when it comes to sustainability, however, its production requires energy and material consumption, that is why an optimal design of a superstructure will lead to the minimum consumption of materials obtaining a more friendly design with nature. It is a global necessity to obtain and deliver concrete structures that meet the conditions of sustainability.
Life cycle management of concrete structures based on sustainability indicators
Authors: Yokota Hiroshi , Nagai Kohei , Sakai Koji
Published: April 2022

A concrete structure should be sufficiently planned, designed, executed and maintained to ensure its requirements during the life cycle. However, structures suffering from serious deterioration in structural members and sometimes subsequent loss in sustainability have been often found due to various reasons. One of the reasons is lack of total management for the structure. To meet these facts, it is extremely important to pursue coordination of engineering work in the design, execution and maintenance stages. The life cycle management is an organized system to support engineers decision to realize sufficient sustainability of the structure in the design, execution, maintenance, and all related work during its life cycle. The life cycle management is implemented based according to the life cycle management scenario in which balance of several sustainability indicators should be considered with ensuring overall sustainability. The sustainability indicators will be determined from the social, environmental and economic points of view. The scenario should be regularly reviewed based on the PDCA cycle and be updated if necessary. This paper deals with the concept and framework of the life cycle management of concrete structures to ensure sustainability during the structural life.