--- title: "Destructive tests of concrete" subject: "Concrete Technology and Masonry Structure" chapter: 5 key: "semester_5/concrete_technology_and_masonry_structure:destructive-tests-concrete" source: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/destructive-tests-concrete site: BCT Engineering --- # Destructive tests of concrete Concrete Technology and Masonry Structure · Chapter 5: Testing of concrete and quality control - Asked in: 2074 Chaitra, 4 marks - Video: [Destructive test on concrete.](https://www.youtube.com/watch?v=OT9BJmN6RMM) — Sachin pd - Answer checked by Claude Sonnet 5.5 on 2026-10-14 - Page: https://www.bctengineer.com/q/semester_5/concrete_technology_and_masonry_structure/destructive-tests-concrete - Whole chapter: https://www.bctengineer.com/md/semester_5/concrete_technology_and_masonry_structure/chapter-5 ## Question What are the destructive tests (DT) of concrete? ## Short answer Destructive tests include compressive strength on cubes/cylinders, split tensile, flexural strength, core tests (average ≥85% fck, no core <75%), pull-out, and load tests (dead load + 1.25 imposed load for 24h). They directly measure strength but damage the specimen. ## Answer Destructive tests (DT) are tests in which the concrete specimen is loaded or cut to failure, so it is damaged or destroyed. They give the direct measure of strength and are the basis of acceptance (IS 456, Cl. 15 and 16). 1. **Compressive strength test** on 150 mm cubes or 150 × 300 mm cylinders (IS 516): the main test. 2. **Split tensile test** on cylinders (IS 5816): indirect tensile strength. 3. **Flexural strength test** on beams 150 × 150 × 700 mm (IS 516): modulus of rupture. 4. **Core test** (IS 516, ASTM C42): 100 mm cores drilled from the structure and tested in compression; the average of cores should be at least 85% of $f_{ck}$, no core below 75%. 5. **Pull-out and bond tests**: a steel bar pulled from concrete to find bond strength. 6. **Load test on the structure or member** (IS 456, Cl. 17.6): the member is loaded with the full dead load plus 1.25 times the imposed load for 24 hours, and the deflection and recovery are checked. 7. **Modulus of elasticity test** and shear tests. **Comparison with NDT:** DT is accurate but expensive, slow and damages the member, while NDT is quick, cheap, and non-damaging but gives only indirect results. ## Check yourself The answer's key points as multiple-choice questions, with the correct option and why. 1. What is a destructive test? A. Specimen loaded or cut to failure, damaging it B. A test with no damage C. A test on fresh mix D. Visual check Answer: A. DT damages or destroys the specimen. (Key point: Definition) 2. What are the core acceptance limits? A. Average 100%, none below 90% B. Average at least 85% of fck, no core below 75% C. Average 75%, none below 85% D. Average 50% Answer: B. Cores: mean ≥ 85% fck and each ≥ 75%. (Key point: Core acceptance) 3. How is the load test applied? A. Twice the dead load for 1 hour B. Imposed load only for 7 days C. Dead load plus 1.25 times imposed load for 24 hours D. Ultimate load until failure Answer: C. IS 456 Cl. 17.6 specifies this. (Key point: Load test) 4. How does DT compare with NDT? A. DT is cheaper B. DT gives only indirect results C. DT is non-damaging D. DT is accurate but expensive, slow and damaging Answer: D. NDT is quick and cheap but indirect. (Key point: DT vs NDT) ## Related in Concrete Technology and Masonry Structure - [Destructive and non-destructive tests in masonry](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Adestructive-ndt-masonry-list) — Concrete Technology and Masonry Structure, chapter 10 - [Non-destructive tests for masonry](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Andt-masonry-tests) — Concrete Technology and Masonry Structure, chapter 10, asked 3× - [Non-destructive testing methods for concrete](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Andt-methods-concrete) — Concrete Technology and Masonry Structure, chapter 5, asked 4× - [Tensile strength tests of concrete](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Atensile-strength-tests) — Concrete Technology and Masonry Structure, chapter 5, asked 2× - [Importance of non-destructive testing](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Andt-importance) — Concrete Technology and Masonry Structure, chapter 5, asked 4× - [Tests for compressive and tensile strength](https://www.bctengineer.com/question.md?key=semester_5%2Fconcrete_technology_and_masonry_structure%3Astrength-tests-compression-tension) — Concrete Technology and Masonry Structure, chapter 5, asked 4× ## Related in other subjects - [Non-destructive tests on insulators](https://www.bctengineer.com/question.md?key=semester_8%2Fhigh_voltage_engineering%3Anon-destructive-insulator-tests) — High Voltage Engineering, chapter 7, asked 4× - [Destructive and non-destructive tests](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Aretrofit-destructive-tests) — Building Technology, chapter 11 - [Non-destructive tests in buildings](https://www.bctengineer.com/question.md?key=semester_6%2Fbuilding_technology%3Andt-building) — Building Technology, chapter 11 - [Asphalt concrete construction and quality control](https://www.bctengineer.com/question.md?key=semester_7%2Ftransportation_engineering_ii%3Aasphalt-concrete-construction) — Transportation Engineering II, chapter 3, asked 5×