The Results Of Air Permeability, Total Water Absorption, And Mortars

Better Essays
Fig. 6 shows the results of air permeability, total water absorption, and voids. R mortars had lower permeability than the mortars with WTS. Air permeability of R was 1.13 x 10-13 m², a value 5 times higher than L60. The air permeability increased with increasing WTS content. The water absorption values ranged from 10.6% to 13.7%, and the voids from 9.6% to 12%. The results show that WTS replacement increased the porosity and permeability of geopolymer mortars. The geopolymer binders with WTS and the additional RHA became the mortars more consistent and difficult to mix and mold, and the entrapped air remained in the mortars.
Fig. 7 shows the capillary water absorption. The higher the WTS content in the mixture, the lower the capillary water
…show more content…
The average penetrations measured in the specimens were: 78.0 mm (R), 58.5 mm (L15), 50.3 mm (L30), and 34.0 mm (L60).
The results show that R mortars had more capillary suction than mortars with WTS. According to Pavía and Treacy (2006), smaller the dimensions and more connected the pores, more evident are the capillary effects. The results of capillary tests show that the pores in R mortars had smaller dimension than WTS mortars and then the water suction was higher. The large pores in mortars with WTS difficult the capillary effect (Liu et al., 2011) and contributed to decrease the mechanical properties (Rovnaník, 2010).
Fig. 8 shows the R and L60 SEM images. Fig. 8a shows a dense matrix with some small pores distributed on material. Fig. 8b shows L60 matrix with higher porosity with larger voids when compared to R. These observations are in accordance with water absorption, voids and capillary water absorption results, which showed that the binder with WTS increased the porosity and decrease the capillary suction of the mortars (caused by the larger pores in sample). Both images revealed homogenous materials, indicating efficient mixing. Fig. 8c and Fig. 8d indicate a good bonding interface
…show more content…
Conclusions

This study reports the partial replacement of MK by non-calcined WTS in the production of geopolymer with sodium silicate from RHA. The results showed that the properties of geopolymers binders are highly dependent on the WTS content in the mixture.
The binder with WTS increased the setting times, kinetics of temperature test showed low rates of geopolymerization reactions.
The workability and the mechanical properties of the geopolymer mortars decreased as the WTS content in the binder increased. The compressive strengths in all curing ages were higher than the minimum required for several types of building components. All of the mortars increased the mechanical properties with time, indicative of continuous reactions. The mortars with geopolymer binders with WTS showed larger voids and lower capillary suction when compared to reference mortars.
The findings of this experimental work show that it is technically feasible to make geopolymer with partial replacement of MK by WTS. RHA can be added to supply SiO2 to keep the molar ratios constant. It is possible to have good environmental benefits and to make an eco-friendly material using WTS and a sodium silicate solution from RHA.

Related Documents

  • Decent Essays

    The spacing between the dielectric values in dispersion spectrum could be attributed to the relative percentage of solute-solvent interaction which showed significantly more clustered structure than either stearic or stearic – nhexanol formation. The thermodynamic parameters are evaluated using Eyring equation is given below…

    • 793 Words
    • 4 Pages
    Decent Essays
  • Decent Essays

    Ternary Systems Case Study

    • 1464 Words
    • 6 Pages

    13 shows dependence of compressive strength on water content of ternary systems. As w/s decreases, total water content in the mix decreases and results in increased strength, except two mixes in series 4 (S4.30 and S4.40). These two mixes include very high filler content at 30-40% in which the decrease of water content might not compensate the strength loss due to the reduction of cementitious materials (MgO + SF). From this figure, the effective range of w/s to achieve the highest strength is found in each series. To achieve the optimal compressive strength of over 80 MPa, the mortar mixtures required low SF content (MgO/SiO2 = 60/40) in combination with low water content of w/s = 0.21-0.27 (equivalent to w/cm = 0.30-0.35 (Table…

    • 1464 Words
    • 6 Pages
    Decent Essays
  • Decent Essays

    Samples without filler, although contain highest gel volume but also requires highest water content in the series (w/b=0.36) and consequently has lowest 28-day compressive strength of 43.7 MPa. The introduction of filler content, as at only 10%, is able to reduce water content dramatically to w/b=0.27, leads to the impressive improvement of compressive strength to 85 MPa. Further increase of filler content to 40% results in higher reduction of water content to as low as w/b=0.21 with only a marginal increase of compressive strength to 87 MPa. Testing results have shown that ternary M-S-H binder systems of MgO-SF-QF have higher compressive strength, compared to binary system without fillers. Crushed quart filler is mainly “inert”at room temperature, however, is able to improve workability considerably in M-S-H ternary system (MgO-SF-QF).…

    • 1558 Words
    • 7 Pages
    Decent Essays
  • Decent Essays

    Though the friction coefficient was lower in deionized water, the corresponding wear rate was much higher than that in seawater. As seen in Fig.5,…

    • 1533 Words
    • 7 Pages
    Decent Essays
  • Decent Essays

    Similar to PC concrete, w/b ratio significantly affects the strength of M-S-H mortar mixtures, demonstrated by the increase of compressive strength at all testing ages as water content decreases. The mortar samples at 28 days age obtained low strength of only 20 MPa with w/b = 0.50 (w/s=0.40) but achieved high strength of approximate 70 MPa as w/b was reduced to 0.34 (w/s=0.27). The effective range of w/b to achieve high strength of over 50 MPa at 28 days age was found to be lower than w/b=0.375 (w/s=0.30). By using superplasticizer and crushed filler, it was able to produce M-S-H mortar to have 90 days compressive strength of up to 90 MPa. The compressive strength of M-S-H mortar are comparable to a number of Portland cement mortar mixes produced by Allena and Newtson (2010) and Al-Jubory (2013) at similar water to binder…

    • 1060 Words
    • 5 Pages
    Decent Essays
  • Decent Essays

    Copper Gta Welding

    • 1640 Words
    • 7 Pages

    The increase in ductility is related to the microstructure of the welds at a temperature below 1058 °C. In this temperature range, the amount of liquids among the α-Cu grains is minute, and the composition of the liquids resembles the eutectic of (Cu+Cu2O). Solidification of Cu+Cu2O eutectics at the tip of cracking hinders the propagation of crack between adjacent α-Cu grains, and in some degree leads to the increase of strength. Thus, the strength of the welds increases from 10.3 Mpa at 1058 °C to 12.2 Mpa at 1053 °C. At 1020 °C, which is close to the lower limit of the welds’ S-L range, the ductility of the welds increases to 0.00493, which is very close to the Δε (0.00508) during welding.…

    • 1640 Words
    • 7 Pages
    Decent Essays
  • Decent Essays

    This can also be seen by the value of the rate constants where k1 k2. Additionally the process of phenol decomposition by direct ozonation is different than that of indirect ozonation. Degradation of phenol by OH radicals favors the formation of aromatic by products, following the formation of organic acids and thereafter partial mineralization [26]. Because the OH radical is a powerful and unselective oxidant, raising the initial Ph values increased TOC removals. The alkaline environment presented a higher degradation rate for the whole duration of 80 minutes than that of the initial pH (pH8.9) and acidic pH (pH4).…

    • 860 Words
    • 4 Pages
    Decent Essays
  • Decent Essays

    Feed Flow Rate Essay

    • 800 Words
    • 4 Pages

    4.2.4 Effect of Feed flow rate (Fgr) on Product Distribution An increase in the flow of gas oil means an increase in the velocity of the gas oil feed, also a decrease in the residence time of the gas oil in the riser; hence a rise in the conversion of gas oil and yields of the products is expected(Akpa et al. 2010). When the flow rate of gas oil is increased, there is an increase in the heat inflow into the reactor, rate of cracking reactions are high, feed also spends less time in the reactor and hence less endothermic cracking reactions take place. This resulted in a slight increase of the conversion of gas oil from 73% - 74% (Fig 4.5). It was observed that as the flow rate of gas oil to the riser increases from 34Kg/s to 63Kg/s the gasoline…

    • 800 Words
    • 4 Pages
    Decent Essays
  • Decent Essays

    He found that heat transfer coefficient increases with increasing aspect ratio and then decreases after a threshold value of 1.266. This has been shown by the CFD analysis. 3. Conclusions There is single chimney flow pattern in case natural convection heat transfer which reduces heat transfer from surface. So making notch is effective method for increasing heat transfer.…

    • 1203 Words
    • 5 Pages
    Decent Essays
  • Decent Essays

    Solubility increases with high temperature and more agitation (stirring). The less the solution is stirred or if there’s a decrease in temperature, the solution becomes less soluble and forms a solid at the bottom of the solution. The forward reaction is endothermic because the deltaHrxn was positive, meaning that the solution was absorbing heat rather than releasing heat. An increase in Kc shows the increase of solubility in borax solution. If there’s a decrease in Kc values, that means there is a decrease in solubility.…

    • 1418 Words
    • 6 Pages
    Decent Essays