GPSC Civil Engineering (Combine Exam) Paper Solution (03-05-26) – Page 2

11) Which of the following statements about aggregate tests as per IS 2386 is incorrect?

1. The ‘Aggregate Impact Value’ (AIV) test measures resistance to sudden impact; IS 383:2016 specifies AIV ≤ 30% for wearing coarse aggregates.
2. The ‘Los Angeles Abrasion Value’ (LAA) test measures resistance to impact; the standard charge consists of 12 steel balls for grading A of aggregate.
3. The ‘Flakiness Index’ and ‘Elongation Index’ are measured separately; a particle is flaky if its least dimension is less than 0.6 times its mean sieve size.
4. The ‘Soundness Test’ (IS 2386 Part 5) uses sodium sulphate or magnesium sulphate solution to assess durability against weathering; magnesium sulphate gives a more severe test.

12) The Culturable Command Area (CCA) for a particular region is 6 Mha, out of which, 4 Mha is being sown in rabi season and 3 Mha in kharif season. These areas are being irrigated to the extent of 60% in rabi and 40% in kharif respectively. The annual intensity of irrigation for this region will be

1. 80%
2. 60%
3. 100%
4. 50%

13) Which of the following types of cement is most suitable for mass concrete construction such as dams, where heat of hydration needs to be minimized?

1. Rapid Hardening Cement (IS: 8041)
2. Sulphate Resisting Cement (IS: 12330)
3. Low Heat Portland Cement (IS: 12600)
4. Portland Pozzolana Cement (IS: 1489)

14) Consider the following statements about aggregates used in concrete:

1. The Fineness Modulus (FM) of fine aggregate should be between 2.0 and 3.5 as per IS:383.
2. The maximum size of aggregate should not exceed one-fourth of the minimum thickness of the member.
3. Flaky and elongated particles decrease the water demand in concrete.

Which of the above statements are correct?

1. 1 and 2 only
2. 2 and 3 only
3. 1 and 3 only
4. 1, 2 and 3

15) In the IS method of concrete mix design, the target mean strength (f’ck) is calculated as:

1. f’ck = fck + 1.65σ
2. f’ck = fck + k x s, where k is the statistical constant
3. The standard deviation values are taken from IS 10262:2019 Table 1 for initial design

Which of the above statements is/are correct?

1. 1 and 3 only
2. 2 and 3 only
3. 1 only
4. 1, 2 and 3

16) Which of the following chemical admixtures is classified as a ‘Superplasticizer’?

1. Calcium Chloride
2. Triethanolamine
3. Sulphonated Naphthalene Formaldehyde (SNF)
4. Calcium Lignosulphonate

17) In extreme weather concreting, which of the following measures is adopted during hot weather concreting as per IS 7861 (Part 1)?

1. Pre-cooling of aggregates and use of chilled water or ice
2. Using accelerating admixtures to speed up setting
3. Increasing the cement content significantly
4. Using rapid hardening cement

18) Consider the following statements about ‘Carbonation’ in concrete:

1. Carbonation reduces the pH of concrete below 9, thereby destroying the passivation layer on reinforcement.
2. Higher water-cement ratio increases the rate of carbonation.
3. Carbonation is not beneficial as it increases the compressive strength of surface concrete.

Which of the above statements is/are correct?

1. 1 and 2 only
2. 3 only
3. 1, 2 and 3
4. 2 and 3 only

19) Consider the following statements about the Sardar Sarovar Dam on the Narmada River:

1. It is a gravity concrete dam.
2. Its Full Reservoir Level (FRL) is 148.68 m.
3. The dam is located at Bharuch district, Gujarat.

Which of the above statements is/are correct?

1. 1 and 2 only
2. 2 and 3 only
3. 1 only
4. 1, 2 and 3

20) Which of the following reservoirs in Gujarat has the highest live storage capacity?

1. Ukai Reservoir (Tapi River)
2. Dharoi Dam (Sabarmati River)
3. Sardar Sarovar Reservoir (Narmada River)
4. Kadana Dam (Mahi River)