Of cement soil specimens. On the other hand, both the Na
Of cement soil specimens. On the other hand, both the Na and SO4 2- within the sodium sulfate resolution participate in the hydration reaction of cement soil to produce ettringite crystalsCrystals 2021, 11,8 of(3CaO l2 O3 CaSO4 2H2 O) and wollastonite (CaCO3 aSO4 aSiO3 5H2 O), among other substances (the particular chemical formula is shown under). These gradually filled the internal pores on the specimens, yielding a denser specimen structure, as a result leading to a rapid increase in dynamic compressive strength inside the 14 d of curing. When the curing IL-7 Proteins custom synthesis period enhanced beyond 14 d, the internal reaction progressively decreased with extended curing period, the generated material decreased correspondingly, and internal pores couldn’t be filled properly. With continuous erosion, the internal structure is steadily destroyed, top to a reduce of dynamic compressive strength. 3CaSO4 4CaO l2 O3 9H2 O 14H2 O 3CaO l2 O3 CaSO4 2H2 O Ca(OH)2 2CaSO4 3CaO l2 O3 aSO4 8H2 O 14H2 O 3CaO l2 O3 CaSO4 2H2 O CaCO3 Ca(OH)2 SiO2 CaSO4 H2 O 12H2 O CaCO3 aCO4 aSiO3 5H2 O Figure 7b shows that below precisely the same curing period situation, the dynamic compressive strength of your cement soil specimens followed a trend of 1st increasing and after that decreasing with growing Na2 SO4 solution concentration. Cement soil specimens having a curing period of 14 d have been analyzed. The dynamic compressive strengths of the cement soil specimens had been 15.63, 16.22, 17.86, 21.29, and 19.14 MPa beneath the action of water and 4 various Na2 SO4 resolution concentrations (1.five, four.5, 9.0, and 18.0 g/L, respectively). At a concentration of Na2 SO4 option of 9.0 g/L, the dynamic compressive strength was maximal, representing increases of 36.22 , 31.26 , 19.23 , and 11.26 compared with water and also the four concentrations of Na2 SO4 option, respectively. The YTX-465 Biological Activity purpose is the fact that at concentrations of Na2 SO4 remedy of 0, 1.five, and 4.five g/L, the SO4 2- content material inside the specimen was low, the reaction generated less material, the pore filling rate was low, as well as the dynamic compressive strength was low. At a concentration of Na2 SO4 option of 18.0 g/L, the SO4 2- content was high, large amounts of ettringite crystals and wollastonite had been generated, along with the internal pores of your specimens had been filled. When the expansion force exceeds the cementing force of the specimen, the internal structure is damaged, resulting within a reduced dynamic compressive strength from the specimen. Multivariate nonlinear fitting from the dynamic compressive strength of your cement soil specimen was carried out for the age of curing and also the concentration of Na2 SO4 answer. The fitting final results are shown in Figure 8. The fitted surface shows an clear arch feature; therefore, the dynamic compressive strength of cement soil specimens reaches the maximum value when the curing period and the concentration of Na2 SO4 resolution attain a precise range. Inside the tested case, the dynamic compressive strength with the cement soil specimens reached the maximum value at a curing period of 14 d and a Na2 SO4 solution concentration of 9.0 g/L. DCS = 7.920 0.892t 1.039 – 0.026t2 – 0.0402 – 0.006t R2 = 0.920 Within this formula, DCS may be the dynamic compressive strength with the cement soil specimen, t would be the curing period from the specimen, and is definitely the mass concentration of the Na2 SO4 remedy. three.3. Absorption Energy In the dynamic effect test, according to the pressure train curves of incident wave, reflected wave, and transmitted wave, the incident power (WI ), r.
