13 Civil Engineering Interview Questions And Sample Answers

By Indeed Editorial Team

Updated 21 September 2022

Published 6 June 2021

The Indeed Editorial Team comprises a diverse and talented team of writers, researchers and subject matter experts equipped with Indeed's data and insights to deliver useful tips to help guide your career journey.

When you apply for a civil engineer's job in a construction company, the employers expect you to have in-depth practical and theoretical knowledge in the construction process. Knowing the types of questions beforehand can bolster your confidence and help you to prepare answers. In this article, we provide you with examples of some common civil engineering interview questions and their answers that you may encounter in an interview.

Related: What Do Civil Engineers Do? (Skills And Career Prospects)

Civil Engineering Interview Questions With Sample Answers

Most civil engineering interview questions can get fairly technical. Accurate responses to technical questions need a thorough understanding of theoretical concepts in civil engineering and practical knowledge of the construction industry. Use these sample questions and their answers as a reference to prepare for a civil engineering interview:

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1. What is reinforced cement concrete?

Sometimes, the interviewers are interested in discussing the details of reinforced cement concrete. They can ask this question to initiate a conversation on this topic. You can start by stating the definition of reinforced cement concrete and then discuss its importance in construction.

Example: "Reinforced Cement Concrete or RCC is a material with a composed unit of strong ductile and high tensile substance such as steel, combined with the rigidity of cement to enhance its elasticity and tensile strength."

2. What are the steps in concreting and curing?

These are follow-up questions after the interviewers ask you about RCC. You can start by listing the steps and subsequently mentioning the methods. Sometimes a panel member can pick one of the steps or methods and ask about the details after you have answered this question. So, try to explain some of these procedures to show that you understand more than just the steps.

Example: "The steps in concreting are: batching of ingredients, mixing ingredients, transporting and placement of concrete, and compacting. Curing concrete ensures maximum strength and proper shape. There are six steps in curing concrete. They are:

  • Creating a structure to shade the concrete surface

  • Waiting for the water sheen to evaporate from the surface

  • Covering the entire concrete surface with a light coloured fabric sheet to keep the concrete moist

  • Spraying water on the fabric regularly, while ensuring there are no pools of water getting created

  • Spreading polyethylene sheets on top and fastening their corners and edges to lock the moisture beneath

  • Repeating the moistening process for five to seven days to get the best results"

Related: Guide: What Is Structural Design In Civil Engineering?

3. Can you explain why curing is not required to be done by creating water pools and polyethylene sheets?

If you answered the curing procedure correctly, the panel members might ask reasons for performing some of the steps in a specific manner. This is an example of a typical follow-up question designed to test in-depth knowledge of concrete curing.

Example: "Water pools or ponds on concrete are only suitable in warm weather where it can evaporate at a sustained rate. In cold weather, the water pools can freeze and expand, affecting the concrete's overall strength. Moreover, creating ponds results in wastage of water. In windy areas, polyethylene sheets can be blown away, increasing the risk of desiccation in the concrete."

4. What is the nominal concrete proportion for different grades?

Some hiring managers often ask this question to check if your fundamentals are strong. It is useful to list the ratios and specify the units to make a better impression.

Example: "The grade-wise concrete proportion is:

M10 = 1:3:4

M15 = 1:2:4

M20 = 1:1.5:3

M25 = 1:1:2

M30 = 1:1:1

where M(n) is the grade, n is the compressive strength measured in Newton/millimetre2, and the ratio represents the proportion of cement with fine aggregate and coarse aggregate."

5. What are the concrete tests?

Interviewers ask this question to see if you are aware of industry-standard quality checks on concrete. Try to list the critical tests and provide reasons. If you know all the tests, you can mention them afterward.

Example: "The two primary concrete tests are compression test and slump test because cement quality is often determined based on its compression and ratio of water and cement. Permeability and rapid chloride ion penetration tests ensure the minimum required density of concrete to avoid rust formation on the steel reinforcement and subsequent cracking and spalling of concrete."

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6. What are the different types of slumps in a slump test?

This question is to check if you know detailed information about a slump test and its results. Mention all three types and give a reasonable explanation about each.

Example: "The three different types of slumps are true slump, shear slump and collapse slump. True slump marks a uniform decrease in mass of concrete in all directions without any signs of disintegration, retaining the overall shape. Shear slump shows that a concrete mixture does not have any cohesion, which results in the shearing of the top portion and a sideways breakdown. Collapse slump happens when the concrete has excessive water in it. It results in bleeding and collapses easily because it is unable to hold any kind of shape."

7. What is bleeding in concrete?

Sometimes, the interviewer may ask this follow-up question if you answered the previous question correctly. This question tests if you know the terminology or if you have just memorised the answers.

Example: "Bleeding is a process in which excess portion of unabsorbed water segregates to the surface in cement hydration."

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8. Why are steel plates inserted inside bearings in the elastomeric bearing?

Topics such as elastomeric bearings test your understanding of support structures and how they play an important role in heavy-duty construction such as suspension bridges. You can use this answer as a start and then elaborate with an example.

Example: "Steel plates are inserted in elastomeric bearing to instil a spring functionality and increase compression stiffness of bearing. This addition limits excessive lateral bulge."

9. What is prestressing?

Some hiring managers can ask this question to check if you know the difference between ordinary RCC and prestressed concrete. A good way to answer this question is to define prestressing and then stating the reinforcements. When listing the techniques, try to mention a brief overview of the processes.

Example: "Prestressing is a construction process that increases the tensile strength of concrete even further than ordinary RCC. The processes used in prestressing are:

  • Spalling reinforcement: Spalling reinforcement is used to prevent the piling up of stresses behind the loaded area of anchor blocks.

  • Equilibrium reinforcement: Equilibrium reinforcement is a way of prestressing with multiple anchorages for sequential loads. It is used to handle concave trajectories of the stresses on the load-line.

  • Bursting reinforcement: To deal with lateral tensile stresses, we use bursting reinforcement on prestressed concrete."

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10. Explain pre-tensioning and post-tensioning.

Sometimes, the interviewer wants to know if your knowledge of prestressing is extensive enough. You can answer this question by mentioning how these methods relate to prestressing and then state the differences between them.

Example: "Pre-tensioning and post-tensioning are two different methods used in prestressing. The core concept involves using tensioned wires or bars of steel as reinforcement structures in cured concrete. In the pre-tensioning method, the wires or bars are anchored to a metal support. Then we use hydraulic jacks to induce tension and fix side moulds. Concrete is then poured around the tensed structure to harden and accommodate the compressive force from the jacks.

The post-tensioning method is similar in concept as far as the placement of cables and concrete is concerned. But, tension is applied to the wires or cables after the concrete is hardened. This method works best for cases where modular concrete units are required to be connected to create a larger member on-site."

11. How are the freeway bridges built?

This question tests your knowledge of public work and the procedure of building bridges.

Example: "First, we are required to take future traffic into account based on existing and projected figures and update the design accordingly. During construction, we place reinforced cement/rebar stanchions over the freeway to accommodate the bridge. Off-ramp and on-ramp are constructed to and from the freeway and bridge. Then, cement slabs are required to be built and placed on the underlying platform."

12. State any incident when you had to face a critical situation.

The employer wants to know whether you have decision-making and problem-solving skills. You can narrate any incident when you solved the problem successfully to answer this question.

Example: "I dealt with a problem on the site of a bungalow construction. While we were constructing an upper slab, I heard a slight cracking noise. I checked the supporting structure immediately and found that it was shaking under the weight of a worker who was standing on top of it. I cautioned him to stop working immediately, get down and reinforce the wooden supports, preventing a major accident."

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13. What are the ethics of civil engineering, according to you?

The answer to this question shows your priorities and work ethic. You can talk about environmental and public health issues if they ask you to elaborate.

Example: "I believe that a civil engineering job involves giving better infrastructure and shelter to people, keeping environmental issues and public health in mind."

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