3.2.3. Net Flexural Strength

A different type of tensile strength test, known as the net flexural strength, is shown in Figure 7. According to the results, concrete's net flexural strength was more significant than its splitting tensile strength. Concrete mixtures constructed with FA artificial LWA had values ranging from 5.41 MPa to 6.62 MPa, while GGBFS and QP artificial aggregates had values ranging from 4.48 MPa to 5.45 MPa and 5.56 MPa to 6.09 MPa, respectively. Particles with a higher crushing strength showed better flexural strength values. While the net flexural strength of artificial LWA concretes was lower than that of normal-weight concrete, the compressive, splitting, and net flexural strengths were all comparable to normal-weight aggregate concrete and it could be improved by improving the cement paste quality and reducing the water-cement ratio. Although the flexural strength of artificial LWA concretes was lower than that of natural normal-weight aggregate concrete, there was a consistency between the compressive strength, tensile strength, and net flexural strength for the artificial LWA concrete.

#### 3.2.4. Load–Displacement Curves

Figure 6 shows typical load–displacement curves for concrete mixtures. Concretes with a lower compressive strength as demonstrated in Figure 8 have more significant displacements based on the load–displacement curve. Concretes constructed with lightweight artificial particles display ductile behavior because their maximum displacement values are more crucial. Adding artificial LWA to a concrete mix improves the concrete's ductility.

**Figure 7.** The net flexural strength of artificial aggregate concrete.

**Figure 8.** *Cont*.

**Figure 8.** Load–displacement curves for (**a**) FAAC, (**b**) GGBFSAC, and (**c**) QAC.

#### 3.2.5. Fracture Energy

A three-point bending machine was used to test a notched beam, and the results are shown in Figure 9. Artificial aggregate concretes constructed from FA, QP, and GGBFS fiberreinforced materials had fracture energies of 391 MPa, 328 MPa, and 310 MPa, respectively. The strength of artificial LWA concrete was reduced when compared to natural normalweight aggregate concrete. The fracture energy is the sum of the actuator's energy and weight. The decreased fracture energy of artificial LWA concretes may be attributed to the results of this calculation. Because of the lower weight of the concrete, the amount of energy given by weight is reduced. The area under the load–displacement curves for concrete created using artificial LWA was less than for concrete manufactured with natural normal-weight aggregate. Since natural normal-weight aggregate has a lower density than artificial aggregate, the fracture energy provided by the actuator in the concrete will be more substantial.

**Figure 9.** Fracture energy of artificial aggregate concretes.

#### 3.2.6. Characteristic Length

Figure 10 depicts the characteristic length values, which are a brittleness measurement. The concrete mixes made using artificial lightweight particles had the most significant characteristic length values. With its distinctive length as a consequence, it is clear that artificial LWA makes concrete more ductile. Because of its higher compressive strength, the stronger concrete also had shorter characteristic length values. This provides further evidence that the ductility of concrete increases with its compressive strength.

**Figure 10.** Characteristic length of artificial aggregate concretes.

#### 3.2.7. Bond Strength

We could determine the concrete's binding strengths using the findings of this experiment. Increasing the FA artificial lightweight replacement boosts the concrete mix's binding strength. The results are shown in Figure 11. GGBFS artificial LWAs increased bond strength at a 20 percent replacement ratio by approximately 42 percent, while increasing the GGBFSA content to 60 percent reduced bond strength by 18 percent. Almost all bond strength tests for quartz artificial aggregate concrete were passed. When compared to natural normal-weight aggregate, manufactured LWA was weaker. This, however, directly affects the steel bar–concrete relationship; pulling out the steel bar easily breaks or crushes the weaker aggregate of the implanted steel bar.

The findings of the other studies demonstrated that artificial LWA works well, if not exceptionally. As a result, concretes constructed using artificial LWA have lower bond strength than concretes made with normal-weight natural aggregate. Thus, bond strength was determined to be the least effective measure when assessing the entire performance of artificial LWA.

**Figure 11.** Bond strength of artificial aggregate concretes.
