scholarly journals Effects of Hollow Sizes on the Properties of Sandcrete Blocks

Author(s):  
O.S. Olagunju ◽  
A.A. Raheem

Two-cell hollow sandcrete blocks constitute the dominant wall construction material for modern shelter in many African countries, especially Nigeria. The hollow cavities in the block have adverse effect on its mechanical characteristics. This study investigated the effects of hollow sizes on the properties of sandcrete blocks. Sandcrete blocks of size 225 × 225 × 450 mm with varying hollow sizes of 175 × 187.5, 173 ×190 and 180 × 210 mm and web thickness 25, 35 and 15 mm respectively; were produced using cement: sand ratio of 1:12. The blocks were tested for compressive strength, density and water absorption. The results indicated that compressive strength at 28 days for blocks with hollow sizes 175 × 187.5, 173 ×190 and 180 × 210 mm are 5.22, 3.64 and 0.41 Nmm-2 respectively. The corresponding densities are 2307.56, 2589.15 and 1715.23 kg/m³ while the rate of water absorption are 22.2, 18.8 and 24.5%, respectively. It was concluded that the larger the size of the hollow in sandcrete blocks the lower their mechanical properties.

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Haiming Chen ◽  
Yangchen Xu ◽  
Donglei Zhang ◽  
Lingxia Huang ◽  
Yuntao Zhu ◽  
...  

This work is aimed to study the possibility of recycling plastic waste (polypropylene (PP)) as aggregate instead of sand in the manufacturing of mortar or concrete. For this, an experimental study was carried out to evaluate the influence of nano-SiO2 and recycled PP plastic particles' content on physical, mechanical, and shrinkage properties and microstructure of the mortars with recycled PP plastic particles. The sand is substituted with the recycled PP plastic particles at dosages (0%, 20%, 40%, and 60% by volume of the sand). The nano-SiO2 content is 5% by weight of cement. The physical (porosity, water absorption, and density), mechanical (compressive and flexural strength) and shrinkage properties of the mortars were evaluated, and a complementary study on microstructure of the interface between cementitious matrix and PP plastic particles was made. The measurements of physical and mechanical properties showed that PP-filled mortar had lower density and better toughness (higher ratio of flexural strength to compressive strength). However, the compressive strength and flexural strength of PP-filled mortar is reduced, and the porosity, water absorption, autogenous shrinkage, and dry shrinkage increased as compared to normal cement mortar. The addition of nano-SiO2 reduced the porosity, water absorption, and drying shrinkage of PP-filled mortar and effectively improved the mechanical properties, but increased its autogenous shrinkage. A microscopic study of the interfacial zone (plastic-binder) has shown that there is poor adhesion between PP plastic particles and cement paste. From this work, it is found that recycled PP plastic waste has a great potential to be a construction material. It can be used as partial replacement of natural aggregates instead.


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.


2008 ◽  
Vol 1 (2) ◽  
pp. 113-120 ◽  
Author(s):  
A. C. Marques ◽  
J. L. Akasaki ◽  
A. P. M. Trigo ◽  
M. L. Marques

In this work it was evaluated the influence tire rubber addition in mortars in order to replace part of the sand (12% by volume). It was also intended to verify if the tire rubber treatment with NaOH saturated aqueous solution causes interference on the mechanical properties of the mixture. Compressive strength, splitting tensile strength, water absorption, modulus of elasticity, and flow test were made in specimens of 5cmx10cm and the tests were carried out to 7, 28, 56, 90, and 180 days. The results show reduction on mechanical properties values after addition of tire rubber and decrease of the workability. It was also observed that the tire rubber treatment does not cause any alteration on the results compared to the rubber without treatment.


2020 ◽  
Vol 849 ◽  
pp. 61-66
Author(s):  
Iswahyuni ◽  
Indri Hermiyati ◽  
Suharyanto ◽  
Uma Fadzilia Arifin ◽  
Dewi Nur Hidayati

Plastic shopping bags are easy to obtain for free or at low prices, hence contribute as the highest quantity among plastic waste. The plastic shopping bags waste has no economic value. Usually they are just thrown away. An alternative solution is by utilizing them to produce paving block by mixing with sands. The objective of this experiment is to evaluate the best ratio composition of plastic shopping bags waste and sand, followed by evaluation of the physical-mechanical properties of this particular paving block. Several different mixture ratios of weights of plastic shopping bag and sand were evaluated to obtain the best physical-mechanical properties of the paving block. The mixture ratios of weight of plastic shopping bags waste and sand were 1:1, 1:2, 1:3, 1:4 and 1:5, respectively. The shopping plastic bags waste was melted before mixed with sand. The different mixture ratios were mixed with same pressure. The paving block mixture with ratio of 1:4 exhibited the best physical-mechanical properties as revealed by no defect, no crack and fine surface. The compressive strength of 17.4 MPa, friction resistance of 0.138 mm/sec and water absorption of 2.518% can be achieved, which is suitable for parking area construction.


Author(s):  
Adegbenle Bukunmi O

Laterite samples from Ede area with particle components of 19.7% clay, 32.8% silt and 47.5% sand was stabilized with combined cement, lime and bitumen and test for Compressive strength, Linear Shrinkage, Permeability and Water Absorption. The stabilizers were mixed with laterite soil in different ratios and percentage. The laterite carried 90% which is constant while the three stabilizers shared the remaining 10% in varying form. After 28 days of curing, laterite stabilizer with 90% of laterite, 8% of cement, 1% lime and 1% bitumen (LCLB1) possessed compressive strength of 2.01N/mm2. It Water Absorption Capacity was 3.05%. LCLB4 stabilizer (90% laterite, 6% cement, 2% lime and 2% bitumen) has the same compressive strength with LCLB1 stabilizer but with a high Water Absorption Capacity of 4.2%. The stabilizer of 90% laterite, 3.33% cement, 3.33% lime and 3.33% of bitumen (LCLB8) has the lowest compressive strength of 0.74N/mm2 and the highest Water Absorption Capacity of 5.39%. The results shows that LCLB1 stabilizer is a better stabilizer for strength and blocks made from laterite stabilized with it stand a good alternative to sand Crete blocks in building constructions. The combination of these stabilizers in order to determine a most economical volume combination for optimum performance is highly possible and economical.


2019 ◽  
Vol 5 (5) ◽  
pp. 1007-1019 ◽  
Author(s):  
Babar Ali ◽  
Liaqat Ali Qureshi ◽  
Ali Raza ◽  
Muhammad Asad Nawaz ◽  
Safi Ur Rehman ◽  
...  

Despite plain cement concrete presenting inferior performance in tension and adverse environmental impacts, it is the most widely used construction material in the world. Consumption of fibers and recycled coarse aggregates (RCA) can add ductility and sustainability to concrete. In this research, two mix series (100%NCA, and 100%RCA) were prepared using four different dosages of GF (0%GF, 0.25%GF, 0.5%GF, and 0.75%GF by volume fraction).  Mechanical properties namely compressive strength, splitting tensile strength, and flexural strength of each concrete mixture was evaluated at the age of 28 days. The results of testing indicated that the addition of GF was very useful in enhancing the split tensile and flexural strength of both RCA and NCA concrete. Compressive strength was not highly sensitive to the addition of GF. The loss in strength that occurred due to the incorporation of RCA was reduced to a large extent upon the inclusion of GF. GF caused significant improvements in the split tensile and flexural strength of RCA concrete. Optimum dosage of GF was determined to be 0.25% for NCA, and 0.5% for RCA concrete respectively, based on the results of combined mechanical performance (MP).


2018 ◽  
Vol 777 ◽  
pp. 465-470
Author(s):  
Sutas Janbuala ◽  
Mana Eambua ◽  
Arpapan Satayavibul ◽  
Watcharakhon Nethan

The objective of this study was to recycle powdered marble dust to improve mechanical properties and thermal conductivity of lightweight clay bricks. Varying amounts of powdered marble dust (10, 20, 30, and 40 vol.%) were added to a lightweight clay brick at the firing temperatures of 900, 1000, and 1100 °C. When higher quantities of powdered marble dust were added, the values of porosity and water absorption increased while those of thermal conductivity and bulk density decreased. The decrease in apparent porosity and water absorption were also affected by the increase in firing temperature. The most desirable properties of the clay bricks were obtained for the powdered marble dust content of 40 vol.% and firing temperature 900 °C: bulk density of 1.20 g/cm3, compressive strength 9.2 MPa, thermal conductivity 0.32 W/m.K, and water absorption 22.5%.


This paper aimed to investigate the mechanical characteristics of HSC of M60 concrete adding 25% of fly ash to cement and sand and percentage variations of silica fumes 0%,5% and 10% to cement with varying sizes of 10mm,6mm,2mm and powder of granite aggregate with w/c of 0.32. Specimens are tested for compressive strength using 10cm X 10cmX10cm cubes for 7,14,28 days flexural strength was determined by using 10cmX10cmX50cm beam specimens at 28 days and 15cm diameter and 30cm height cylinder specimens at 28 days using super plasticizers of conplast 430 as a water reducing agent. In this paper the experimental set up is made to study the mechanical properties of HSC with and without coarse aggregate with varying sizes as 10mm, 6mm, 2mm and powder. Similarly, the effect of silica fume on HSC by varying its percentages as 0%, 5% and 10% in the mix studied. For all mixes 25% extra fly ash has been added for cement and sand.


2020 ◽  
Vol 322 ◽  
pp. 01039
Author(s):  
Lais Alves ◽  
Nordine Leklou ◽  
Silvio de Barros

Concrete is a major construction material that produces high levels of carbon dioxide in its manufacturing process. Hence the construction sector is responsible for relevant environmental impacts. This justifies the need to find materials as green and ecological alternatives to common Portland cement. Geopolymers represent the most promising alternative due to its proven durability, mechanical and thermal properties. This study investigates the effects of solid-to-liquid and alkali activator ratios on the synthesis of slag-based pure geopolymer and their relation to the geopolymerization process. Two activating solutions were used: a) a mixture of sodium hydroxide, sodium silicate, and water; and b) a mixture of potassium hydroxide solution, potassium silicate, and water. As precursor material, ground blast furnace slag was used. Precursors and activators were mixed with solid-to-liquid ratios in range of 1.5 to 2.2. In the first stage of the study, the mechanical properties were evaluated for each activating solution. In the following stage, different formulations, with variations in the water percentage and solid-to-liquid ratio were tested for mechanical properties and SEM observations. Test results indicate that the resulting geopolymer has the potential for high compressive strength and is directly affected by the composition of the activating solution. It can also be observed that compressive strength was affected by solid-to-liquid ratio and % of water added to the mixture, and strength increased with ageing day.


2020 ◽  
Vol 833 ◽  
pp. 228-232
Author(s):  
Md. Jihad Miah ◽  
Mohammad Shamim Miah ◽  
Anisa Sultana ◽  
Taukir Ahmed Shamim ◽  
Md Ashraful Alom

This work performs experimental investigations on concrete made with difference replacement percentage of first-class burnt clay brick aggregate (0, 10, 20, 30, 40, 50, 60, 80, and 100%) by steel slag (SS) aggregate. The aim is to evaluate the mechanical properties as well as durability performances, additionally, water absorption porosity test is performed to investigate the influence of steel slag aggregate on the durability of tested concrete. The experimental results have shown that the compressive strength was improved significantly due to the replacement of brick aggregate by steel slag aggregate. The crushing strength of concrete made with 100% steel slag aggregate has gained up to 70% more than the control concrete (100% brick aggregate). However, the porosity of concrete was reduced with the adding percentage of brick aggregate by steel slag aggregate which is consistent with the compressive strength results. Further, a quite good agreement between compressive strength and porosity was observed as well.


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