Fly Ash Experiment

Class F fly ash are obtained from Hangzhou Yi-solid New Material Technology Co., Ltd. China, used as a based materials. Distilled Water, Polyvinyl Alcohol (PVA) fibers, Sodium Hydroxide (NaOH), Liquid sodium silicate (Na2SiO3), Magnesium Sulphate (Mg2SO4) and silica nanoparticles (30±5 nm) were purchased from Macklin, China. To execute this study, natural sand having less than 0.5mm particle size and 2.52 value of fineness modulus was employed. All the chemicals used were analytical grade.

Sample preparation:
To prepare the alkali activator 10M NaOH was mixed with Na2SiO3 solution in the weight ratio of 1:2. In a Hobart mixer the total fly ash was mixed with 3%, 5% and 7% of PVA fibers. X-ray fluorescence measured the chemical composition of fly ash and is given in Table 1. Natural sand was mixed to the fly

Split tensile strength tests were conducted after 28 days of curing. To calculate the properties of each specimen the testing setup is shown in Fig.1A. The splitting tensile strength is calculated using the following equation:
T=2P/πDL……….. (1)
Where T = splitting tensile strength in (MPa) P = maximum load on the specimen in (N) D = diameter of the specimen in (mm) and L = length of the specimen in (mm) Up to first crack strength this Eq. is valid, however it can also be used to depict the tensile response beyond the first crack strength, in such case T is taken as an effective tensile stress. Flexural
The flexural test was conducted as per ASTM C348 standard specification [29]. The test was performed on the three-point bend test prisms specimens (Fig.1B).The loading rate applied on the specimens was 0.5 kN/s. The flexural strength is determined according to the equation given in ASTM C348 as:
S_f=0.0028P………. (2)
Where Sf = flexural strength in (MPa) and P = maximum load in (N) Durability Measurement: Ultra-sonic pulse velocity