scholarly journals Chemical and Mechanical Differences between Historic and Modern Scots Pine Wood

Heritage ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 116-127
Author(s):  
Kate Hudson-McAulay ◽  
Craig J. Kennedy ◽  
Michael C. Jarvis
Keyword(s):  
Scots Pine ◽  
Building Materials ◽  
Chemical Mechanism ◽  
Small Samples ◽  
Ftir Microscopy ◽  
Modern Material ◽  
Historic Building ◽  
Acetyl Content ◽  
Loss Of Strength

Timber is one of the most common historic building materials, but relatively little is known about how it ages in situ. Here we investigate historic and modern Scots pine to determine any chemical or mechanical differences between them. Fourier-transform infrared (FTIR) microscopy was used to investigate differences in the chemical composition of Scots pine (Pinus sylvestris L.) timber, comparing small samples from historic beams about 500 years old with modern timber. The hemicellulosic acetyl content was reduced by about half in the historic samples, uniformly across the thickness of the beams. A chemical mechanism was therefore suggested for the loss of acetyl groups, as has been observed in paper. In paper, deacetylation and the resulting release of acetic acid are accompanied by loss of strength. Mechanical testing of the historic timber was difficult because the available length of the samples along the grain was only 20 mm. After developing a miniaturized compression test developed for the purpose, it was shown that the relative stiffness of the historic Scots pine samples was reduced by about half compared to modern material.

scholarly journals Fire Resistance Behaviour of Geopolymer Concrete:An Overview

Buildings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 82
Author(s):  
Salmabanu Luhar ◽  
Demetris Nicolaides ◽  
Ismail Luhar
Keyword(s):  
Compressive Strength ◽  
Thermal Resistance ◽  
Building Materials ◽  
Elevated Temperatures ◽  
Construction Materials ◽  
Flexural Behavior ◽  
Thermal Shrinkage ◽  
Physico Chemical ◽  
The Impact ◽  
Loss Of Strength

Even though, an innovative inorganic family of geopolymer concretes are eye-catching potential building materials, it is quite essential to comprehend the fire and thermal resistance of these structural materials at a very high temperature and also when experiencing fire with a view to make certain not only the safety and security of lives and properties but also to establish them as more sustainable edifice materials for future. The experimental and field observations of degree of cracking, spalling and loss of strength within the geopolymer concretes subsequent to exposure at elevated temperature and incidences of occurrences of disastrous fires extend an indication of their resistance against such severely catastrophic conditions. The impact of heat and fire on mechanical attributes viz., mechanical-compressive strength, flexural behavior, elastic modulus; durability—thermal shrinkage; chemical stability; the impact of thermal creep on compressive strength; and microstructure properties—XRD, FTIR, NMR, SEM as well as physico-chemical modifications of geopolymer composites subsequent to their exposures at elevated temperatures is reviewed in depth. The present scientific state-of-the-art review manuscript aimed to assess the fire and thermal resistance of geopolymer concrete along with its thermo-chemistry at a towering temperature in order to introduce this novel, most modern, user and eco-benign construction materials as potentially promising, sustainable, durable, thermal and fire-resistant building materials promoting their optimal and apposite applications for construction and infrastructure industries.

scholarly journals Susceptibility of earth-based construction materials to fungal proliferation: laboratory and in situ assessment

2019 ◽  
Vol 3 ◽  
pp. 140-149 ◽  
Author(s):  
Alexis Simons ◽  
Alexandra Bertron ◽  
Christophe Roux ◽  
Aurélie Laborel-Préneron ◽  
Jean-Emmanuel Aubert ◽  
...  
Keyword(s):  
Air Quality ◽  
Manufacturing Process ◽  
Building Materials ◽  
Construction Materials ◽  
Microbial Density ◽  
Microbial Proliferation ◽  
Materials Used ◽  
Ecological Construction ◽  
The Impact

The impact of building materials on the environment and the health of occupants is nowadays a priority issue. Ecological construction materials such as earthen materials are currently experiencing a regain of interest due to both ecological and economic factors. The microbial proliferation on indoor materials can induce a deterioration of the building air quality and lead to an increase of health risks for the occupants. The issue of indoor air quality raises questions about the use of earthen building materials and their possible susceptibility to fungal development. The microflora of earthen materials and their ability to grow on such support are indeed poorly studied. This study focused on the quantification of both bacterial and fungal microflora along the manufacturing process. The impact of extreme humidity, simulating a hydric accident, on microflora development was analyzed on the surface and inside earthen bricks. The initial microflora of these materials was dramatically reduced during the manufacturing process, especially after heat treatment for drying. Proliferation of remaining microorganisms was only observed under high humidity condition, in particular for earthen materials with vegetal aggregates. Moreover, in situ samplings were performed on naturally dried earthen materials used in buildings. The characterization of the microbial density revealed a higher microbial density than on manufactured specimens, while microbial concentration and detected taxa seemed mainly related to the room use and building history. These results provide a better understanding of microbial proliferation on these materials.

Effect of soil physical properties on the long-term performance of planted Scots pine in Finnish Lapland

2010 ◽  
Vol 90 (3) ◽  
pp. 451-465 ◽  
Author(s):  
K. Mäkitalo ◽  
V. Alenius ◽  
J. Heiskanen ◽  
K. Mikkola
Keyword(s):  
Physical Properties ◽  
Water Content ◽  
Scots Pine ◽  
Soil Physical Properties ◽  
Height Growth ◽  
Site Preparation ◽  
Preparation Methods ◽  
Finnish Lapland

Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies L. Karst.) forests dominate in Finnish Lapland. This study examined the long-term effects of soil physical properties and conditions measured in intact intermediate areas, as well as site preparation, on the survival and height growth of planted pine on eight experimental sites, 25-27 yr after reforestation. On the four originally spruce-dominated sites, pine survival was the highest on sites with a high soil air-filled porosity (AFP) near saturation (at -1 kPa), a high van Genuchten parameter, and a low soil water content (SWC) in situ, and height growth was the fastest on sites with a high soil AFP in situ and a high van Genuchten parameter n, and on sites reaching a soil AFP of ca. 0.20 m3 m-3 at a high matric potential after saturation. Survival, but not mean height, was enhanced on the spruce sites by intensive site preparation methods such as ploughing instead of lighter site preparation methods. On the four originally pine-dominated sites, site preparation affected the mean height but not survival. The use of SWC as a sole criterion for sites suitable for pine reforestation was tested and found to be uncertain. Key words: Boreal forest soils, soil water content, air-filled porosity, van Genuchten function, site preparation, reforestation, Scots pine

scholarly journals Flame-Retardant and Smoke Suppression Properties of Nano MgAl-LDH Coating on Bamboo Prepared by an In Situ Reaction

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Xiaoling Yao ◽  
Chungui Du ◽  
Yating Hua ◽  
Jingjing Zhang ◽  
Rui Peng ◽  
...  
Keyword(s):  
Reaction Time ◽  
Flame Retardant ◽  
Building Materials ◽  
Reaction Times ◽  
Step Method ◽  
In Situ Reaction ◽  
One Step ◽  
Double Hydroxide ◽  
Optimal Reaction

In recent years, bamboo has been widely used for building materials and household goods. However, bamboo is flammable, so a flame-retardant treatment for bamboo is urgently needed. In this work, nano MgAl-layered double hydroxide (MgAl-LDH) coated on bamboo, which was called MgAl-LB, was synthesized by an in situ one-step method. To determine the optimal in situ time, the effects of different reaction times on LDH growth on the bamboo surface and the flame retardancy of the MgAl-LBs were investigated. The SEM observations show that LDH growth on the surface of bamboo was basically saturated when the in situ reaction time was 24 h. Abrasion experiments show that MgAl-LDH coating has good abrasion resistance. The fire performance of the MgAl-LBs was evaluated by cone calorimeter tests, which indicated that the THR and TSP of the MgAl-LBs were significantly lower than those of untreated bamboo. Taking into account the energy consumption problem, determining the reaction time of 24 h is the optimal reaction time. Compared with untreated bamboo, the THR and TSP of MgAl-LB prepared at 24 h decreased by 33.3% and 88.9%, respectively.

Attenuated Total Internal Reflection Infrared Microspectroscopy For The Study Of Trace Contaminants In Aqueous Solutions.

1999 ◽  
Vol 5 (S2) ◽  
pp. 66-67
Author(s):  
Andre’ J. Sommer ◽  
Mark Hardgrove
Keyword(s):  
Infrared Spectroscopy ◽  
Total Internal Reflection ◽  
Molecular Spectroscopy ◽  
Internal Reflection ◽  
Small Samples ◽  
Attenuated Total Internal Reflection ◽  
Infrared Microspectroscopy ◽  
Transmission Measurements ◽  
Major Emphasis

Over the past several years many developments have taken place in the field of molecular spectroscopy. For Raman spectroscopy many of the improvements have arisen from technological innovations that include diode-based lasers, holographic notch filters and charged coupled detectors. In contrast, a majority of the developments in infrared spectroscopy have been in the area of new sampling accessories. A major emphasis has been placed on attenuated total internal reflection (ATR) accessories. The devices are allowing infrared spectroscopy to be employed in process control environments and quality control laboratories where the method is not only robust but has the advantages of limited sample preparation and/or in situ analysis.In the realm of microspectroscopy, ATR accessories have the added advantages of providing better spatial resolution, equal to or higher S/N for equivalent sample size compared to transmission measurements and most importantly the ability to collect spectra of small samples without the adverse effect of diffraction. One accessory which was developed several years ago is known as the Split-Pea.

Historic building materials from Alhambra: Nanoparticles and global climate change effects

2019 ◽  
Vol 232 ◽  
pp. 751-758 ◽  
Author(s):  
Marcos L.S. Oliveira ◽  
Carolina Dario ◽  
Bernardo F. Tutikian ◽  
Hinoel Z. Ehrenbring ◽  
Caliane C.O. Almeida ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
Building Materials ◽  
Global Climate ◽  
Historic Building ◽  
Climate Change Effects

Does climate-related in situ variability of Scots pine (Pinus sylvestris L.) needles have a genetic basis? Evidence from common garden experiments

2019 ◽  
Vol 39 (4) ◽  
pp. 573-589 ◽  
Author(s):  
Artur Jankowski ◽  
Tomasz P Wyka ◽  
Roma Żytkowiak ◽  
Darius Danusevičius ◽  
Jacek Oleksyn
Keyword(s):  
Pinus Sylvestris ◽  
Scots Pine ◽  
Genetic Basis ◽  
Common Garden ◽  
Common Garden Experiments

scholarly journals Samples of concrete of small sizes

2019 ◽  
Vol 91 ◽  
pp. 02043
Author(s):  
Andrew Varlamov ◽  
Sergey Tverskoi ◽  
Vadim Gavrilov
Keyword(s):  
Reinforced Concrete ◽  
Strain State ◽  
Concrete Structures ◽  
Small Samples ◽  
Reinforced Concrete Structures ◽  
Standard Samples ◽  
Stress Strain ◽  
Strength And Deformation ◽  
Loss Of Strength ◽  
Reference Samples

The article analyzes the sizes of concrete samples. We revealed a possibility to reduce sizes of samples. We simultaneously carried out tests of standard and small (25x25x100 mm) concrete samples. Small samples were obtained by cutting standard samples. In the course of study, the density, strength, and deformation of standard and small specimens were measured. The results are presented in tables and graphs. The strength of small samples was lower than the strength of reference samples. We identified loss of strength of the samples when cutting concrete. The average characteristics of deformation of concrete remained. Small samples are recommended for use in assessing the stress-strain state of reinforced concrete structures.

In Situ Measurement of Thermal Resistance of Building Envelope at the Residential Occupancy in Indonesia

2015 ◽  
Vol 771 ◽  
pp. 191-194 ◽  
Author(s):  
Wahyu Sujatmiko ◽  
Hermawan Kresno Dipojono ◽  
F.X. Nugroho Soelami ◽  
Soegijanto
Keyword(s):  
Thermal Resistance ◽  
High Performance ◽  
Building Materials ◽  
Precast Concrete ◽  
Green Building ◽  
Building Envelope ◽  
Building Wall ◽  
Ashrae Standards ◽  
Building Walls

Abstract. This paper presents the measurement results of three building wall materials which are commonly used for residential housings in Indonesia, namely clay brick, batako (concrete brick), and precast concrete. In-situ measurement of the steady state thermal flow (heat flux) at building walls (envelopes) is conducted in order to determine the thermal resistance of building wall according to ASTM C1155. The results show that all three building materials having a thermal resistance values are far below the energy conservation provisions of ASHRAE 90.1 and especially when compared to the provision of high performance green building ASHRAE 189.1 It is found that precast concrete has higher thermal resistance (or has lower thermal conductivity) than that of other two materials, hence a better compliance to the ASHRAE standards.

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