Assessing Disaster Resilience of Concrete with Titanium Dioxide Nanoparticles

To begin, prepare four groups of specimens using a concrete mix of Portland CPII cement, crushed stone, medium washed river sand, and water, maintaining a water-to-cement ratio of 0.5. For each 3.63-kilogram specimen, weigh appropriate amounts of cement, sand, gravel, and add water. Homogenize all components thoroughly to obtain the most uniform mass possible.

Cast the mixed concrete into the molds and inspect the mixture for signs of aggregate segregation, free water accumulation or staining from unmixed material to ensure a uniform consistency for representative results. Now, mold the test specimens in cylindrical metal forms 10 centimeters in diameter and 20 centimeters in height. Fill each mold so the concrete reaches the designated level with uniform distribution.

Produce sample A and designate it as the negative control without any additives to serve as the baseline for comparison with the other specimens. Produce sample B by incorporating 1%nanotitanium dioxide, approximately 36.3 grams, into the concrete mix. Distribute the nanoparticles evenly across the mass to prevent agglomeration.

Similarly, prepare samples C and D, ensuring homogeneity among the sample sets. Now, prepare sample E by incorporating a 3%copper-based plasticizer additive, approximately 108.9 grams, into the concrete mix, and designate this sample as the positive control to compare the effect of the plasticizer relative to the other samples. Store all samples in an area with controlled conditions protected from environmental influences to await the curing time.

Here are the specimens in a humidity-controlled area maintained at a temperature of around 23 degrees Celsius and a relative humidity of at least 95%for 24 hours. After this initial period, submerge the specimens in lime-saturated water, maintained at the same temperature of 23 degrees Celsius for continued curing over the designated period. After curing, remove the specimens and measure the weight of each specimen to confirm that each has an average mass of 3.63 kilograms.

Condition the specimens at room temperature of around 23 degrees Celsius, according to the following schedule. Subject each specimen to an axial compression test using a universal tensile and compression testing machine. Ensure that the load cell capacity of the testing machine is compatible with the specimen dimensions, and verify that a digital control system is enabled for real-time monitoring and recording of the applied load.

Continue applying the compressive load until the specimen fails and record the maximum supported load at the moment of rupture. Compute the compressive strength of each specimen using the formula. Then conduct the compressive strength test by positioning each cylindrical specimen measuring 100 millimeters in diameter and 200 millimeters in height vertically at the center of the hydraulic press.

Ensure proper contact between the specimen and the loading plates. Apply the axial load continuously and without impact at a rate of around 0.45 megapascals per second. Repeat this procedure for all three specimen sets.

Control, titanium dioxide-doped and copper-based additive samples. Record all values systematically for later comparison among the different sample sets. Finally, compare the recorded compressive strength values to assess the mechanical behavior and performance differences between the control, titanium dioxide-doped and copper-based additive specimens.

Compression tests showed that concrete specimens containing 1%titanium dioxide by mass had higher compressive strength than both the control concrete and those with 3%copper-based plasticizer. Among samples subjected to 28 days of curing during compressive strength testing, specimens B3, C3 and D3 appeared visibly lighter in color than specimens labeled A3 and E3.The specimen labeled B had the highest compressive strength after 28 days of curing at 17, 379 megapascals. Specimens labeled A and E showed lower compressive strength values after 28 days of curing, with values of 13, 018 and 9, 725 megapascals respectively.