bluuebunny/crossref_metadata_2025_split huggingface dataset:
Joints in masonry walls
Authors: Galman Iwona , Jasiński Radosław 
Published: September 2018

AbstractA correct design project should not only control the load‐bearing capacity and stability of the individual elements but also ensure proper cooperation between these elements. Connection of masonry walls is crucial for durability of the building, safety of its users, and thermal insulation of external walls. The design and construction process is successful only if loads can be transferred properly between the particular structural elements. The issue of joints between the walls and consequent transferring of vertical and horizontal loads between them is still not sufficiently recognized. Very few tests have been performed on this issue, while operating standards require that the designer ensures proper cooperation between intersecting walls. In this paper, information is collected on the code requirements, design procedures, producer's recommendations as well as the laboratory tests results, and conclusions in the topic of joints in masonry walls. Additionally, results of preliminary tests performed by the authors on the joints of autoclaved aerated concrete (AAC) masonry walls are presented.
The design of storey height elements for the inner leaf of masonry cavity walls
Authors: Roberts John , Fudge Cliff 
Published: September 2018

AbstractHistorically, codes of practice, such as the United Kingdom code CP111, dealt with walling rather than concrete or masonry as separate materials. CP111 was withdrawn in 1985 following the publication of BS5628 Part 2 but other European standards do still indicate that masonry design procedures may be used for the design of cavity walls constructed with a prefabricated inner leaf. Reinforced and unreinforced panels of autoclaved aerated concrete (AAC) have been manufactured for many years in Europe but have never proved to be particularly popular in the United Kingdom except for specialist applications, such as mansard roofs. In 2008, BS EN 12602, dealing with prefabricated reinforced components of AAC and which covers plain AAC panels containing reinforcement for handling, was published. EN 1996‐1‐1 (Eurocode 6), which is the current structural design code for masonry, does not directly limit the size of unit that can be considered as masonry but does require masonry units to be manufactured in accordance with the relevant BS EN 771 series standard, which in the case of AAC is BS EN 771‐4. This paper looks at the issues involved in designing the inner leaf of an external cavity wall using storey height elements in accordance with EN 1996‐1‐1.
Aluminum silicate recycling raw materials for production of autoclaved aerated concrete
Authors: Matsushita Fumiaki , Imasawa Kouichi , Shibata Sumio , Horiguchi Masatoshi 
Published: September 2018

AbstractAluminum silicate recycling raw materials such as tiles and pot shards waste, in which the main phases were Al‐Si‐O amorphous with Mullite and α‐Quartz, were subjected to the utilization for the production of autoclaved aerated concrete (AAC). In case of adding silica gel or fine‐grinded quartz sand for production of AAC, tobermorite formation is declined. By adding tiles waste up to 33% substitution for silica sand, tobermorite formation is improved. Tobermorite formation is not altered by fineness of tiles waste. The possibility of replacing silica sand by tiles and pod shards waste at the amount of up to 27% for AAC panels and blocks is confirmed.
An innovative application of autoclaved aerated concrete technology
Authors: Riepe Frank W. 
Published: September 2018

AbstractAutoclaved aerated concrete (AAC) has failed to gain a foothold in the North American construction market despite its popularity in Europe. In North America the most common wall construction technology with a stucco finish, except in certain niche markets, is the exterior insulation finish system (EIFS). Because of the limitations of EIFS, a wall assembly technology has been developed that marries frame construction of all types with 75 mm thick AAC blocks and medium‐density sprayfoam polyurethane insulation. This composite technology allows more rapid assembly and higher performance than conventional AAC block construction. The completed stucco‐finished wall has much higher thermal resistance, load and shear strength, water and vapor resistance, and acoustical performance than single‐wythe AAC block construction. In North America, where AAC is used very little, this technology will allow much broader acceptance as even more benefits will be realized over prevailing technologies. This technology, known as System5zero, has two patents in the United States and is approaching commercialization. This paper and presentation will discuss development, testing, benefits, and applications of System5zero.
Application of recycled waste material for the production of autoclaved aerated concrete
Authors: Seifert Severin , Liesch Anna‐Lena , Thome Volker , Dittrich Sebastian , Wolfram Daniela 
Published: September 2018

AbstractThe construction industry is one of the most resource‐intensive industries in the world, and at the same time no industry causes more waste. These two facts are crucial factors that have a strong impact on our environment. On the one hand, primary natural resources for high‐quality products are becoming increasingly scarce and, on the other hand, the dumping of mineral waste is causing great problems. Therefore, it is important to conserve natural resources and avoid the dumping of waste. The AAC industry is also a resource‐intensive industry. Although AAC waste in the form of split and sludge is already being reused in production, large quantities of natural quartz sand are still being used. There is still potential here to spare primary resources. This article is intended to give an overview of the results of several studies with the aim to use residual mineral masses in AAC production as a substitute of quartz sand. Therefore, it was investigated to what extent the fine fraction of processed waste concrete as well as the fine fraction of sorted construction waste can be used in production of AAC as a secondary raw material. It could be shown that, especially when using SiO2‐rich mixtures, a large part of the natural quartz sand in the AAC can be replaced.
Autoclaved aerated concrete (AAC) rubble for new recycling building products: In dry premixed mortars for masonry, in masonry blocks, and in lightweight blocks
Authors: Hlawatsch Frank , Aycil Hakan , Kropp Jörg 
Published: September 2018

AbstractIn cooperation of Bremen Institute for Materials Testing (MPA Bremen), a Department of Leibniz Institute for Materials Engineering IWT, Bremen University of Applied Sciences and the Research Association RWB Bremen building products for masonry structures were developed on the basis of autoclaved aerated concrete (AAC) rubble from C&D wastes. Granulates from processed AAC rubble were introduced as aggregates in dry premixed masonry mortars, in masonry blocks, and lightweight building blocks and elements to replace completely natural aggregates. These recycling products exhibit beneficial technical properties, at the same time, large volumes of AAC wastes may be re‐used. On the basis of the achieved R&D results from laboratory experiments, trial batches of dry premixed mortar and masonry blocks were produced in the building materials industry on their available industrial equipment, minor adjustments in the mix composition were necessary. After a sufficient amount of dry premixed mortar and masonry blocks were produced, the recycling products were used to erect indoor masonry walls in a building project in Bremen.
Seismic performances of AAC masonry: A review of experimental and numerical approaches
Authors: Miccoli Lorenzo 
Published: September 2018

AbstractAutoclaved aerated concrete (AAC) has been of growing interest for its structural performances, thanks to its high strength‐to‐weight ratio and low bulk density. The prominent advantage of AAC is its lightweight, this aspect in seismic‐prone areas can be beneficial for the seismic performances of a building. The focus of this paper is to provide an overview of seismic performance of load‐bearing masonry made of AAC, based on the past studies carried out in this field. Results on the assessment of the in‐plane cyclic response of walls with and without reinforcements are reported. In addition, the response of an AAC confined masonry buildings tested on the shaking table is presented. The second part of the paper shows the numerical simulation of the building response based on linear and nonlinear static (push‐over) methods. According to authors’ findings, unreinforced AAC masonry buildings with a regular geometry can face low to medium seismic events. For severe seismic events, a significant damage can be expected in AAC multistorey buildings. To achieve higher seismic performance, the AAC masonry must be combined with other structural systems as confined masonry or bed‐joint reinforced walls.
The sustainability of wall solutions: Life Cycle Assessment (LCA) of different solutions for external closures
Authors: Paleari Michele , Miliani Alessandro 
Published: September 2018

AbstractIn building's sustainability assessment, the role of the main construction materials is crucial. Even though the number of components is very high, the heaviest environmental impacts are due to a very short list, which comprises structures and envelope. For this reason, good environmental performances of walls materials are the base for achieving high sustainability levels for the building. The Life Cycle Assessment (LCA) is a consolidated scientific method for the analysis of the environmental profile of products, processes, and services taking into account the energy consumptions and the environmental impacts. Therefore, it is more and more applied in the construction sector to analyze the sustainability of products, certified with the Environmental Product Declaration (EPD). A research was conducted with the aim to compare the environmental performances of different solutions of building enclosures, highlighting the positive behavior of the autoclaved aerated concrete (AAC) blocks. The study was updated after 3 years, underlining the positive effects of some improvements in the production process of AAC on the environmental profile of the construction solutions. The environmental profile of the AAC blocks was measured through the LCA and the results were certified by an EPD that thus could be a useful tool for the sustainability communication from producers to architects and engineers.
The use of EN771‐4 the European harmonized AAC masonry unit product standard in the UK
Authors: Primmer Peter 
Published: September 2018

AbstractEuropean product standards for masonry units came fully into effect in the UK in 2006 replacing existing UK standard BS6073 Part 1 and 2 that had covered many types of masonry units. EN 771 Part 4 is the product standard specifically for AAC masonry units with reference to supporting test methods. This paper deals with the successful implementation of EN 771 Part 4 in the UK and will be of general interest to those attending the conference. There will be comments on the key physical characteristics of AAC, the relationship of evaluation methods to the declared finished product properties, and how these properties align with UK regulatory requirements. It will be shown that the UK successfully integrated European harmonized standards to confirm that UK AAC masonry unit products continually meet all performance requirements.
ENSUBA–A new method for solving the gypsum problem in waste autoclaved aerated concrete
Authors: Liesch Anna‐Lena , Thome Volker , Dittrich Sebastian 
Published: September 2018

AbstractAccording to a previous study, the existing building stock in Germany contains up to 10% of gypsum building material, which is integrated in walls, ceilings, and floors. After the demolition of these buildings and their reuse in recycling building material (RC building materials), gypsum causes severe problems, such as sulfate attack and the corresponding concrete damages. Due to these problems the majority of the gypsum‐containing demolition waste is deposited in landfill sites. The other option – recycling the autoclaved aerated concrete (AAC) – is very difficult: according to the current technological standards and a previous study, almost all AAC formulations contain a certain amount of sulfate mineral phases in the form of gypsum or anhydrite. The use of the sulfate minerals is necessary for production reasons and to meet mechanical material requirements such as compressive strength and shrinkage. In this work a method known from the conservation and restoration field where ammonium carbonate compresses are used to remove gypsum from paintings and frescos is modified and applied to AAC recycling. It could be shown that the calcium sulfate phases can be removed to an amount, which allows to use AAC as an RC material or to make deposition much easier.
Circular economy potential for autoclaved aerated concrete
Authors: Kreft Oliver 
Published: September 2018

AbstractIn the present paper, a reuse strategy for autoclaved aerated concrete (AAC) demolition waste into the ongoing production of AAC is described. The challenge is huge: The decisive factor for successful recycling is primarily the quality of the AAC recyclate. This must be carefully analyzed before the material is reintroduced into the production cycle. Since 2010, Xella has been investigating how and in what quantities residual AAC from demolished buildings or landfills can be recycled for producing new AAC. Around 10%–and even up to 15%, depending upon its quality–of the pure AAC from landfills can be recycled for new production. In this pilot study, we investigate the chemical and mineralogical composition of the supplied building waste. Among others, the study focuses on the analysis of heavy metals, polycyclic aromatic hydrocarbon (PAH), sulfate, and total organic carbon (TOC) contents. This activity is Xella's preparation for the European Waste Framework Directive, pursuant to which at least 70% of all construction and demolition waste (CDW) must be recycled after 2020. It must furthermore be expected that building material manufacturers will be faced with a take back obligation for building materials once this directive enters into effect.
Investigations about porosity analyzing of AAC
Authors: Anders Nicole 
Published: September 2018

AbstractAutoclaved aerated concrete (AAC) as a building material is characterized by its very good thermal insulation. This is achieved by a very high porosity of the microstructure. The size of the pores ranges from millimeters to nanometers and depends on the position as well as on the origin of the pore. It can be distinguished in propellant pores, web pores, and intercrystalline or interparticle pores. Because of the broad pore size range it is not fully understood until now, which pore sizes significantly and to what extent affect the building material qualities. The AAC's entire pore size distribution can only be detected by the combination of different microstructure analysis methods. For this purpose the nitrogen sorption analysis, mercury intrusion, and 3‐D microcomputer tomography was used as an effective combination. AAC samples that show different mineralogical phase compositions because of the differentiation of the formulation, were tested. On the basis of these samples and the pore size distribution, which is usually used for the description of the frost and frost‐deicing salt resistance of concrete, initial insights into the influence of the respective pore size on building material properties of the AAC could be gained.
Innovations in the crystalline structure forming and its effects on the mechanical performance of AAC
Authors: Kavas Taner , Tan Abdullah , Tiriç Utku , Durğun Abdullatif 
Published: September 2018

AbstractThis study is mainly focused on the crystalline structure and mechanical properties of autoclaved aerated concrete (AAC) without losing any other specific performances such as low bulk density and good thermal insulation capacity. For this purpose, colemanite (C) was added in a proportion of 0.3, 1, 3, 10, 15, 20, and 30% by weight to standard G2/350 receipt during raw material mixing process. After mixing, mud prepared with the suitable amount of starting materials with water was slipping into the laboratory scale metal moulds. Moulded samples were cured under the condition of 55% humidity and 50–55°C for 4 h and sent to autoclave line. Cut‐sized samples were left under the 12 bars pressure for 5 h. Density (Kg/m3), lambda values (W/mK), and compressive strength (MPa) of the samples have been measured. Selected samples that have the highest mechanical strength were examined mineralogically (XRD) and microstructurally by scanning electron mircoscope (SEM). The results show that boron atoms from calcined colemanite (CC) diffused into the tobermorite crystalline structure and remained as an interstitial atom in this structure. Thus, mechanical performance of samples with CC increased more than double time according to the standard G2/350 recipe.
Exosite 1 thrombin inhibition with JNJ-64179375 inhibits thrombus formation in a human translational model of thrombosis
Authors: Wilson Simon J , Connolly Thomas M , Peters Gary , Ghosh Atalanta , Johnson Maureen , Newby David E 
Published: September 2018

AbstractAimsJNJ-64179375 (hereafter JNJ-9375) is a first-in-class, highly specific, large molecule, exosite 1 thrombin inhibitor. In preclinical studies, JNJ-9375 demonstrated robust antithrombotic protection with a wider therapeutic index when compared to apixaban. The purpose of the present study was to examine for the first time the antiplatelet, anticoagulant and antithrombotic effects of JNJ-9375 in a translational model of ex vivo human thrombosis.Methods and resultsFifteen healthy volunteers participated in a double-blind randomized crossover study of JNJ-9375 (2.5, 25, and 250 μg/mL), bivalirudin (6 μg/mL; positive control), and matched placebo. Coagulation, platelet activation, and thrombus formation were determined using coagulation assays, flow cytometry, and an ex vivo perfusion chamber, respectively.JNJ-9375 caused concentration-dependent prolongation of all measures of blood coagulation (prothrombin time, activated partial thromboplastin time, and thrombin time; P < 0.001 for all) and agonist selective inhibition of thrombin (0.1 U/mL) stimulated platelet p-selectin expression (P < 0.001) and platelet-monocyte aggregates (P = 0.002). Compared to placebo, JNJ-9375 (250 μg/mL) reduced mean total thrombus area by 41.1% (95% confidence intervals 22.3 to 55.3%; P < 0.001) at low shear and 32.3% (4.9 to 51.8%; P = 0.025) at high shear. Under both shear conditions, there was a dose-dependent decrease in fibrin-rich thrombus (P < 0.001 for both) but not platelet-rich thrombus (P = ns for both).ConclusionExosite 1 inhibition with JNJ-9375 caused prolongation of blood coagulation, selective inhibition of thrombin-mediated platelet activation, and reductions in ex vivo thrombosis driven by a decrease in fibrin-rich thrombus formation. JNJ-9375 represents a novel class of anticoagulant with potential therapeutic applications.
Comparing retainers constructed on conventional stone models and on 3D printed models: a randomized crossover clinical study
Authors: Mohd Tahir Norhidayah , Wan Hassan Wan Nurazreena , Saub Roslan 
Published: September 2018

Summary

Objectives
The aim of this study was to compare vacuum-formed thermoplastic retainers (VFRs) constructed on stone models (VFR-CV) and those constructed on three-dimensional (3D) printed models (VFR-3D) based on patients’ perspective and post-treatment stability.

Study design
The research was designed as a crossover, randomized control trial.

Materials and methods
Subjects comprised patients receiving fixed appliances at a teaching institution and indicated for VFRs. Post-treatment stone models were scanned with a structured-light scanner. A fused deposition modelling machine was used to construct acrylonitrile-butadiene-styrene (ABS)-based replicas from the 3D scanned images. VFRs were fabricated on the original stone and printed models. Analysis comprised independent t-tests and repeated measures analysis of variance.

Randomization
Subjects were allocated to two groups using Latin squares methods and simple randomization. A week after debond, subjects received either VFR-CV first (group A) or VFR-3D first (group B) for 3 months, then the interventions were crossed over for another 3 months.

Blinding
In this single-blinded study, subjects were assigned a blinding code for data entry; data were analysed by a third party.

Outcome measures
The primary outcome measured was oral health-related quality of life (OHRQoL) based on Oral Health Impact Profile-14 (OHIP-14). Secondary outcome was post-treatment stability measured using Little’s Irregularity Index (LII).

Results
A total of 30 subjects (15 in each group) were recruited but 3 dropped out. Analysis included 13 subjects from group A and 14 subjects from group B. Group A showed an increase in LII (P < 0.05) after wearing VFR-CV and VFR-3D, whereas group B had no significant increase in LII after wearing both VFRs. Both groups reported significant improvement in OHRQoL after the first intervention but no significant differences after the second intervention. LII changes and OHIP-14 scores at T2 and T3 between groups, and overall between the retainers were not significantly different. No harm was reported during the study.

Conclusion
VFRs made on ABS-based 3D printed models showed no differences in terms of patients’ OHRQoL and stability compared with conventionally made retainers.

Registration
NCT02866617 (ClinicalTrials.gov).
The Role of Mixed Reality Simulation for Surgical Training in Spine
Authors: Coelho Giselle , Defino Helton L.A. 
Published: September 2018

Study Design.
This study shows the first phase of validation of a new model for realistic training on spine surgery, conducted from January 2014 to November 2015.

Objective.
To propose and validate a new tool for neurosurgical education, associating virtual and realistic simulation (mixed reality), for spine surgery.

Summary of Background Data.
Surgical simulation is a relatively new filed that has a lot to offer to neurosurgical education. Training a new surgeon may take years of hands-on procedures, increasing the risk to patient's safety. The development of surgical simulation platforms is therefore essential to reducing the risk of potentially serious risks and improving outcome.

Methods.
Sixteen experienced spinal surgeons evaluated these simulators and answered the questionnaire regarding the simulation as a beneficial education tool. They evaluated the simulators in regard to dissection by planes, identification of pathology (lumbar canal stenosis), instrumentation and simulation of cerebrospinal fluid (CSF) leak, and the relevant aspects of the computerized tomography (CT) imaging.

Results.
The virtual and physical simulators for spine surgery were approved by an expert surgery team, and considered adequate for educational purposes. The proportion of the answers was estimated by the confidence intervals.

Conclusion.
The surgery team considered that this virtual simulation provides a highly effective training environment, and it significantly enhances teaching of surgical anatomy and operative strategies in the neurosurgical field. A mixture of physical and virtual simulation provided the desired results of enhancing the requisite psychomotor and cognitive skills, previously acquired only during a surgical apprenticeship. The combination of these tools may potentially improve and abbreviate the learning curve for trainees, in a safe environment.

Level of Evidence: 3