scholarly journals Geopolymer foam as a passive fire protection

2018 ◽  
Vol 247 ◽  
pp. 00031 ◽  
Author(s):  
Michał Łach ◽  
Dariusz Mierzwiński ◽  
Kinga Korniejenko ◽  
Janusz Mikuła

More than 200 firefighters and 40 fire engines were involved in battling the blaze of Grenfell Tower in June 2017. Despite the heroic efforts of fire brigades the more than 80 people died. In the expert opinion the reason such size of the tragedy were the cladding - installed on in a recent renovation - has come under scrutiny, with experts saying a more fire-resistant type could have been used. The use of such type of cladding was probably price. The main motivation of research work is to develop cheap and fire resistant material for buildings and applications in civil engineering structures. The main aim of the research was development of foamed geopolymers based on fly ash and investigation their properties. The research methods used were: coefficient thermal conductivity test, fire-resistant test, visual analyses, density measurement and compressive strength test. The results show the foamed geopolymers has low coefficient thermal conductivity between 0.068 and 0.126 W/(m·K). They have excellent fire and heat resistant facilities, including resistance of this type of materials to the erosive action of fire. Moreover, they have reasonable mechanical properties - they were characterized by compressive strength between 0.5 and 3.5 MPa depending on the density, which ranged from 250 to 700 kg/m3. The conducted research confirmed that geopolymers have the highest fire resistance classes and can be used on a wide scale as a material for protection against various types of fire and as fire-resistant insulation materials in construction.

2014 ◽  
Vol 2 (1) ◽  
pp. 75-82
Author(s):  
Elivs M. Mbadike ◽  
N.N Osadebe

In this research work, the effect of mound soil on concrete produced with river sand was investigated. A mixed proportion of 1.1.8:3.7 with water cement ratio of 0.47 were used. The percentage replacement of river sand with mound soil is 0%, 5%, 10%, 20%, 30% and 40%. Concrete cubes of 150mm x 150mm x150mm of river sand/mound soil were cast and cured at 3, 7, 28, 60 and 90 days respectively. At the end of each hydration period, the three cubes for each hydration period were crushed and their average compressive strength recorded. A total of ninety (90) concrete cubes were cast. The result of the compressive strength test for 5- 40% replacement of river sand with mound soil ranges from 24.00 -42.58N/mm2 a against 23.29-36.08N/mm2 for the control test (0% replacement).The workability of concrete produced with 5- 40% replacement of river sand with mound soil ranges from 47- 62mm as against 70mm for the control test.


Author(s):  
Muhammad Arslan ◽  
Muhammad Asif Saleem ◽  
Maria Yaqub ◽  
Muhammad Saleem Khan

The focus of this research work was to analyse the effect of different types of curing oncompressive strength of concrete structures. For this purpose, 54 test specimens of cylindrical shape wereprepared. These specimens were cured with different methods and were tested on different age days toanalyse the effect of curing on compressive strength. Test specimens cured with conventional water curingmethod gives the highest results as compared to the other adopted methods.


Author(s):  
Archibong Ukeme Donatus ◽  
Ojeagah Kenneth ◽  
Michael Christopher Ukuegboho ◽  
I. E. Chiedu ◽  
Obasuyi Emmanuel Idemudia

This research work involved the preliminary studies of CaAl-LDHs using co precipitation method and applying it in the preparation of concrete to evaluate the compressive strength in grade 15 concrete. Slum and compressive strength test were carried out on the concrete control and concrete mixed with CaAl-LDH, Scanning electron microscope (SEM) and X-Ray Diffractogram (XRD) was carried out on the synthesize LDH, concrete control, and concrete mixed with LDH. From the results obtained in the work failure load test, it was observed that there was an increase by 62.60% in the compressive strength of concrete mixed with 30kg of CaAl-LDHs, the SEM micrograph also shows the increase in the density and the less porosity of the concrete mixed with CaAl-LDH which explained the increase in the compressive strength of the concrete. CaAl-LDH has therefore shows a promising effect on the increase on the compressive strength of concrete.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Levent Bostanci ◽  
Ozlem Celik Sola

Compressive strength, thermal conductivity coefficient, and porosimetric properties of alkali-activated slag (AAS) mortars containing silica aerogel were investigated experimentally in this study. For this purpose, slag mortar mixtures at 0.75% and 1.0% aerogel content ratios were prepared, and these mortar mixtures were activated with lithium carbonate (Li2CO3) at 0.03% and 1.50% dosage rates. Mortar samples were exposed to curing process in water for 2, 7, and 28 days, and the samples, which completed the curing stage, were subjected to the compressive strength test. The porosimetry test and the thermal conductivity coefficient measurement were carried out following the compressive strength test on 28-day samples. The varying aerogel content rate in the mixtures and the effects of the dosage of Li2CO3 on the gel, capillary, and macropore distributions, and the effect of changing porosimetric properties on compressive strength and thermal conductivity coefficient were analyzed in detail. Experimental studies have shown that AAS mortars including an optimum 0.75% aerogel content rate and 0.03% Li2CO3 activation provided a compressive strength of 34.1 MPa and a thermal conductivity coefficient of 1.32 W/mK. Aerogel addition provides a partial compressive strength increase at 7- and 28-day samples while it also causes maximum strength loss of 5.0% at 2-day samples.


2020 ◽  
Vol 39 (2) ◽  
pp. 332-337
Author(s):  
A. O. Alejo

Sandcrete blocks comprise of water, natural sand cement. Sandcrete blocks are the building units used in the construction of wall and partitions. Diverse sizes of sandcrete blocks are used to construct free standing walls and building structure with load and non – load bearing units. This research work investigate and compared strength of sandcrete blocks produced with fine aggregate from different source in Owo local government area. The targeted areas within Owo local government are Emure, Ipele and Shagari. Sieve analysis was conducted on the samples and the result revealed that all the samples are good for sandcrete block production. Thirty six sandcrete cubes samples were mould. The mix proportion 1:6 was used. Batching by volume was adopted. Curing was done by full immersion of sandcrete and compressive strength test was carried out on each specimen at 7, 14. 21 and 28 days respectively. The percentage of fine aggregate used in this research was 100% for all samples. The results revealed that sandcrete blocks produced with fine aggregate from Ipele, Shagari and Emure gives compressive strength of 4,15N/MM2, 3.56N/MM2 and 5.48N/MM2 at 28 days respectively. Based on the result of this research work, it is recommended that Emure fine aggregate (sand) is considered as most suitable out of the samples tested for sandcrete blocks production. Keywords: Sand, Sandcrete blocks, Compressive strength, Curing, Production practice.


Author(s):  
Muhammad Junaid Iqbal

This research work aims at the development of a material model for concrete block masonry used in the load-bearing wall as well as masonry infill. To accomplish this, various tests were performed on concrete block (solid) units and concrete block masonry assemblage. A concrete block having a size of 12 x 8 x 6 inches, were fabricated in a mortar ratio of 1:4, 1:2:2, 1:8 and 1:4:4. The compressive strength of concrete block prisms having size 24.36 x 8.04 x 18.72 inches, was also determined by conducting the compressive strength test. The shear strength of square prisms, having size 26.76 x 8.04 x 25.20 inches, was found by applying diagonal loading. To investigate the bond shear strength of concrete block masonry, triplet tests were carried out on block masonry prisms. Before conduct, a test on block assemblage specimens, the constituent materials of block assemblage i.e. block and mortar were also tested for different properties. The average compressive strength of concrete block (12”x8”x6”) was 302.25 psi and the average unit weight was 119.83 lb/ft3. The compressive strength of mortars of 1:4, 1:2:2, 1:8 and 1:4:4 was 2367, 1752,815 and 1332 psi respectively.


2020 ◽  
Vol 108 (2) ◽  
pp. 203
Author(s):  
Samia Djadouf ◽  
Nasser Chelouah ◽  
Abdelkader Tahakourt

Sustainable development and environmental challenges incite to valorize local materials such as agricultural waste. In this context, a new ecological compressed earth blocks (CEBS) with addition of ground olive stone (GOS) was proposed. The GOS is added as partial clay replacement in different proportions. The main objective of this paper is to study the effect of GOS levels on the thermal properties and mechanical behavior of CEB. We proceeded to determining the optimal water content and equivalent wet density by compaction using a hydraulic press, at a pressure of 10 MPa. The maximum compressive strength is reached at 15% of the GOS. This percentage increases the mechanical properties by 19.66%, and decreases the thermal conductivity by 37.63%. These results are due to the optimal water responsible for the consolidation and compactness of the clay matrix. The substitution up to 30% of GOS shows a decrease of compressive strength and thermal conductivity by about 38.38% and 50.64% respectively. The decrease in dry density and thermal conductivity is related to the content of GOS, which is composed of organic and porous fibers. The GOS seems promising for improving the thermo-mechanical characteristics of CEB and which can also be used as reinforcement in CEBS.


2018 ◽  
Vol 17 (9) ◽  
pp. 2023-2030
Author(s):  
Arnon Chaipanich ◽  
Chalermphan Narattha ◽  
Watcharapong Wongkeo ◽  
Pailyn Thongsanitgarn

2020 ◽  
Vol 38 (10A) ◽  
pp. 1522-1530
Author(s):  
Rawnaq S. Mahdi ◽  
Aseel B. AL-Zubidi ◽  
Hassan N. Hashim

This work reports on the incorporation of Flint and Kaolin rocks powders in the cement mortar in an attempt to improve its mechanical properties and produce an eco-friendly mortar. Flint and Kaolin powders are prepared by dry mechanical milling. The two powders are added separately to the mortars substituting cement partially. The two powders are found to improve the mechanical properties of the mortars. Hardness and compressive strength are found to increase with the increase of powders constituents in the cement mortars. In addition, the two powders affect water absorption and thermal conductivity of the mortar specimens which are desirable for construction applications. Kaolin is found to have a greater effect on the mechanical properties, water absorption, and thermal conductivity of the mortars than Flint. This behavior is discussed and analyzed based on the compositional and structural properties of the rocks powders.


Alloy Digest ◽  
2020 ◽  
Vol 69 (11) ◽  

Abstract Meehanite GB300 is a pearlitic gray cast iron that has a minimum tensile strength of 300 MPa (44 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. This grade exhibits high strength while still maintaining good thermal conductivity and good machinability. It is generally used for applications where the thermal conductivity requirements preclude the use of other higher-strength materials, such as spheroidal graphite cast irons, which have inferior thermal properties. This datasheet provides information on physical properties, hardness, tensile properties, and compressive strength as well as fatigue. It also includes information on low and high temperature performance as well as heat treating, machining, and joining. Filing Code: CI-75. Producer or source: Meehanite Metal Corporation.


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