Laboratory dilatometry and field test to assess durability of masonry

2016 ◽  
Vol 40 (5) ◽  
pp. 425-443 ◽  
Author(s):  
Blair Williams ◽  
Russell Richman
Keyword(s):  
Moisture Content ◽  
Three Dimensional ◽  
Brick Masonry ◽  
Clay Brick ◽  
Critical Moisture Content ◽  
Load Bearing ◽  
Freeze Thaw ◽  
Closed Cell ◽  
Critical Moisture ◽  
Representative Samples

This article analyses the use of dilatometry to assess the durability of load-bearing clay brick masonry in a century home in Toronto (Canada). The building had recently undergone the addition of medium density closed-cell polyurethane spray-applied foam insulation on all interior sides of the exterior clay brick load-bearing walls, increasing the insulating value in areas to RSI 7.9 m2K/W, on average, from the original RSI 0.5 m2K/W, on average. The critical moisture content (saturation degree) of representative samples from the building were compared with values obtained from frost dilatometry testing. The later indicate critical moisture content for freeze–thaw. The frost dilatometry method was furthered by studying three-dimensional testing, rather than the traditional two-dimensional approach. The results showed the brick masonry in the study building are at a relatively low risk of freeze–thaw damage thanks to good resistance of freeze–thaw of the subject brick masonry and low wetting potential of the brick masonry on site. This further strengthens the need for good water shedding characteristics.

scholarly journals Assessment of load bearing clay brick masonry for analyzing long-term durability through field measurement and visual review

2021 ◽  
Author(s):  
Blair E. Williams
Keyword(s):  
Three Dimensional ◽  
Brick Masonry ◽  
Clay Brick ◽  
Saturation Point ◽  
Load Bearing ◽  
Freeze Thaw ◽  
Uniform Manner ◽  
Mosaic Images

This thesis examines a load bearing clay brick century home research house in Toronto (Canada) which has recently undergone the addition of polyurethane foam insulation on all interior sides of the exterior clay brick load bearing walls, increasing the insulating value in areas to RSI 7.9 W/m2K, on average. This study introduces and advances techniques to create high-resolution stitched mosaic images of the elevations to visually document the current physical condition of the brick. The critical saturation point was used to determine the capabilities of the clay brick masonry to resist freeze-thaw damage by way of frost dilatometry testing and compared to measurements taken by in-situ moisture content sensors in the brick masonry. This project also reveals how bricks expand and deteriorate in non-uniform manner during saturated three-dimensional dilatometry testing.

scholarly journals Assessment of load bearing clay brick masonry for analyzing long-term durability through field measurement and visual review

2021 ◽  
Author(s):  
Blair E. Williams
Keyword(s):  
Three Dimensional ◽  
Brick Masonry ◽  
Clay Brick ◽  
Saturation Point ◽  
Load Bearing ◽  
Freeze Thaw ◽  
Uniform Manner ◽  
Mosaic Images

This thesis examines a load bearing clay brick century home research house in Toronto (Canada) which has recently undergone the addition of polyurethane foam insulation on all interior sides of the exterior clay brick load bearing walls, increasing the insulating value in areas to RSI 7.9 W/m2K, on average. This study introduces and advances techniques to create high-resolution stitched mosaic images of the elevations to visually document the current physical condition of the brick. The critical saturation point was used to determine the capabilities of the clay brick masonry to resist freeze-thaw damage by way of frost dilatometry testing and compared to measurements taken by in-situ moisture content sensors in the brick masonry. This project also reveals how bricks expand and deteriorate in non-uniform manner during saturated three-dimensional dilatometry testing.

Study on Critical Moisture Content of Unsaturated Evaporation

2014 ◽  
Vol 513-517 ◽  
pp. 2643-2646
Author(s):  
Hua Zhang ◽  
Wen Long Hu ◽  
Jin Lu Cao
Keyword(s):  
Moisture Content ◽  
Thin Layer ◽  
Measuring System ◽  
Evaporation Process ◽  
Critical Moisture Content ◽  
Whole Process ◽  
Critical Moisture ◽  
Three Stages ◽  
Soil Water Characteristic Curves ◽  
Water Contents

Thin layer evaporation tests of three types of soil were conducted by a newly designed humidity-controllable evaporation and penetration measuring system and lasted for 8 days. The whole process of sample mass variation from wet to dry was recorded in the laboratory. The critical moisture content and air-dried moisture content were obtained from evaporation curve, which divided the evaporation process of thin layer unsaturated soil into three stages, including stable rate stage, reducing rate stage and residual stage. The soil water characteristic curves of soils were predicted by Arya and Paris model, the results showed that the critical moisture contents of evaporation process were the same with the water contents corresponding to residue values of SWCC, it is significant to studying on unsaturated evaporation process.

scholarly journals Impact of fast and slow desiccation on Garcinia imberti seed and seedling vigour

2018 ◽  
Vol 5 (3) ◽  
pp. 95-102
Author(s):  
M Anto ◽  
C Anilkumar
Keyword(s):  
Moisture Content ◽  
Initial Moisture Content ◽  
Germplasm Conservation ◽  
Seedling Vigour ◽  
Critical Moisture Content ◽  
Normal Seedling ◽  
Southern Western Ghats ◽  
Mean Germination Time ◽  
Critical Moisture ◽  
Activated Silica Gel

Garcinia imberti Bourd. endemic to the southern Western Ghats is classified as endangered by the IUCN (2018). The seeds as the sole means of propagation with initial moisture content (MC) of 62.8% are sensitive to desiccation. Studies on the responses of the seed to drying require ascertaining of the critical moisture content (CMC) as a basic requisite for germplasm conservation. Responses of G. imberti seeds to fast drying with activated silica gel (25 ± 2 °C, 6 ± 1% RH) and to slow drying under laboratory conditions (28 ± 2°C, 60 ± 2% RH) were evaluated for seed and seedling vigour. When the MC was reduced to 56% by 48 hours of slow drying or 6 hours of fast drying, 75 to 90% normal seedlings were produced respectively. In the case of fast dried seed (6 hours), seed associated parameters except mean germination time showed peak values with maximum germination and enhanced root length. Below the CMCs of 16.4 and 26.3% (fast and slow drying respectively), half of the tested seeds become non viable. Thus for germplasm conservation the present study proposes 6 hour’s of fast drying to retain viability and normal seedling development of G. imberti.

scholarly journals Testing methods of moisture content, critical moisture content, and germination of jamblang (Syzygium cumini (L.) Skeels) seed

2019 ◽  
Vol 8 (1) ◽  
pp. 47
Author(s):  
Miraz Nur Indraeni ◽  
Faiza Chairani Suwarno ◽  
Abdul - Qadir
Keyword(s):  
Seed Germination ◽  
Moisture Content ◽  
Seed Quality ◽  
Block Design ◽  
Syzygium Cumini ◽  
Critical Moisture Content ◽  
Testing Method ◽  
Randomized Complete Block Design ◽  
Final Count ◽  
Critical Moisture

Jamblang (Syzygium cumini (L.) Skeels) researches are still focused to identify the plant benefits, but that leads to efforts to obtain good seed quality hasn’t been done. This study aims to determine the moisture content testing method, the critical moisture content, and germination testing method (sowing media and first and final count of seed germination). Improving procedure for moisture content testing and identified the best media for germination testing was arranged in a Completely Random Design.  Determining jamblang seeds critical moisture content was arranged in a Randomized Complete Block Design. The experiments were repeated four times. Moisture content with slicing method obtained 49.57%. Jamblang seeds critical water content is 41.61% with 50% germination. The best method of germination was sand medium with fresh seeds (90%). The first count of jamblang seed germination occurs on 32 days after sowing and final count on 83 days after sowing.

scholarly journals Risk of Moisture in Diffusionally Open Roofs with Cross-Laminated Timber for Northern Coastal Climates

Buildings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 10
Author(s):  
Agnieszka Sadłowska-Sałęga ◽  
Krzysztof Wąs
Keyword(s):  
Moisture Content ◽  
Indoor Air ◽  
Oriented Strand Board ◽  
Layer System ◽  
Critical Moisture Content ◽  
Cross Laminated Timber ◽  
Safe Level ◽  
Roof Structure ◽  
Calculation Results ◽  
Critical Moisture

The paper is an attempt to answer the question whether the material-optimized roof construction using cross-laminated timber (CLT) is safe in terms of moisture content in the demanding northern costal climates. The proposed roof structure meets the strength requirements. The partition is diffusionally open, which facilitates moisture transport. However, there is a concern whether the applied layer system allows maintaining a safe level of moisture content below critical moisture content (CMC), which has been set at 20%. The article presents the annual hygrothermal calculation of the proposed roof slope for four locations of northern Europe and Greenland characterized by costal or subpolar climate. Four scenarios of indoor air relative humidity were considered: free floating, RHmin = 40%RH, RHmin = 50%, RHmin = 60%. In all cases, the minimum indoor temperature was 20 °C. The analysis was carried out using WUFI®Plus software. The calculation results showed that the moisture content did not exceed 20% in the CLT layer at any of the described locations. However, for the two coldest climates the assumed level of safety has been exceeded in the roof oriented strand board (OSB) sheathing.

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