Answer only 6.38 6.38 What is the source of fly ash? Why is fly ash sometimes added to concrete?What are the different classes of fly ash?6.39A materials engineer is working in a research project to evaluate the effect ofone type of admixture on the compressive strength of concrete. She tested 10mortar cubes made without admixture and 10 others with admixture after 28days of curing. The compressive strengths of cubes without admixture were25.1, 24.4, 25.8, 25.2, 23.9, 24.7, 24.3, 26.0, 23.8, and 24.6 MPa. The compres-sive strengths of cubes with admixture were 25.3, 26.8, 26.5, 24.5, 27.2, 24.8,24.1, 25.9, 25.3, and 25.0 MPa. Using the statistical t-test, does this admixtureshow an increase in the compressive strength of the cement mortar at a levelof significance of 0.05?

Given : fly ash To determine : 1)source of fly ash 2)Why added in concrete 3)Different class of…

Answered: 6.38 What is the source of fly ash? Why…

6.38 What is the source of fly ash? Why is fly ash sometimes added to concrete? What are the different classes of fly ash?

Construction Materials, Methods and Techniques (MindTap Course List)

4th Edition

ISBN:9781305086272

Author:William P. Spence, Eva Kultermann

Publisher:William P. Spence, Eva Kultermann

Chapter7: Concrete

Section: Chapter Questions

Problem 6RQ: How does the addition of air-entraining materials to Portland cement improve the concrete?

See similar textbooks

Related questions

Q: For the beam and loading shown in the figure, (a) draw the shear and bending-moment diagrams, and…

A: First calculate the reactions using equilibrium equations. Then calculate the shear and bending…

Q: 1. Seach, list and explain the Laws governing the practice of Civil Engineering in the Philippines.…

A: It is asked to explain about the laws governing the practice of civil engineering in the…

Q: Which checks are essential to perform for a successful design of deep foundation?

A: Context: Checks for the design shallow foundation

Q: A 18KN/m 6m 45 KN.m 4m B

Q: . Power is transmitted through a shaft, rotating at 2.5 Hz (150 rpm). The mean torque on the shaft…

Q: 6m 4m W dead 0.9 x 12kN/m =10.8kN/m B A 3m C 3m D E 3m Wwind=1.3 x 60kN/m = 78kN/m

Q: 2. A cylindrical pressure vessel is a fabrication from steel plating that fits to the following…

A: Reference : Engineering mechanics, Circumferential stress and Longitudinal stress Given data :…

Q: 1. A ten-story building is to be constructed at a site where the water table is close to the ground…

Q: Determine the magnitude of the pin force at A. Assume W = 535 lb, a = 4.6 ft, b = 3.5 ft, r = 9 in.…

Q: Determine the size of the circular spiral column to support an axial dead load of 625 kips and a…

A: Given data : Axial dead load = 625 kips Live load = 325 kips f'c = 4 ksi and fy = 60 ksi Steel ratio…

Q: The results of a CPT test performed for a commercial site are presented in the image (You already…

A: In geotechnical engineering, cone penetration tests (CPT) are used to map soil profiles and assess…

Q: Q1. A centrifugal pump has a power input of 20 hp, pumps water at the rate of 400 gpm, and produces…

Q: Bearing Capacity Example: 1 • A square footing 2.5m x 2.5m is shown in the figure below. Determine…

Q: A beam with the cross-section shown is subjected to a vertical shear of 28 kN. Determine: (a) the…

Q: (ii) A hydraulic jump is formed in a 5 m wide outlet at a short distance downstream of control gate.…

Q: 6 kip/ft 3 ft 3 ft D * 6 ft 6 kip/ft B Determine the resultant internal loadings acting on the cross…

Q: Determine the size of the circular spiral column to support an axial dead load of 625 kips and a…

Q: What is PD 1096. Explain

Q: A railroad track is laid at a temperature of 15 oF with gaps of 0.01 feet between the ends of the…

Q: Bearing Capacity An embankment is to be constructed with granular soil (bulk unit weight = 20 kN/m³)…

A: Given data- An embankment with granular soil- Bulk unit weight γb=20 kN/m3 Shear strength S=Cohesion…

Q: 2. Compute by hand and tabulate station elevations and the 1st and 2nd differences for an equal…

A: Data given G1 =+3.5% G2 =-4 % Station PVI = 12+65 Elevation PVI = 300 ft Length of curve, L = 750 ft…

Q: 2. A propeller shaft is subjected to maximum compressive direct stress of 20 N/mm² and maximum shear…

Q: A steel rod 75 inches long with a cross sectional area of 0.25 in2 is held vertically firm at one…

Q: The clockwise angular velocity of the link AB shown in (Figure 1) is WAB = 3.2 rad/s. Figure 1 of 1…

Q: 18. A masonry dam of trapezoidal cross section, with one face vertical has thickness pf 60cm at the…

Q: 2.6-What is the safe stopping distance for a section of rural freeway with a design speed of 80 mi/h…

Q: . Calculate the hydrostatic pressure at A (inside of the water tank) in unit of lbf/ft².

A: ##Determination of Hydrostatic Pressure at A (inside water Tank) in lbf/ft2 #

Q: A propeller shaft is subjected to maximum compressive direct stress of 20 N/mm² and maximum shear…

Q: The mechanism shown in (Figure 1) is used in a riveting machine. It consists of a driving piston A,…

A: Given: vA = 22 m/s Span CD = 150 m Span AC = 300 mm

Q: Solve: A 130-mm-thick-one-way slab is reinforced with 12-mm-diameter tension bars spaced at 110 on…

A: Given data : Thickness = 130 mm Diameter of tension bars = 12 mm , Spacing = 110 Concrete cover = 20…

Q: The Fleming Innovation Center is nearing completion, and the engineers are preparing to create a…

Q: write the equation for shear that you need to estimate the shear's magnitude at D. Estimate the…

Q: 11. Find the total distance that a car travelled from the time the driver saw a hazard when he was…

Q: Q6) A foundation 3.5 m square is to be constructed at a depth of 1.2 m in a deep sand deposit, the…

A: Data given 3.5 square foundation D = 1.2 m WT = 3m below γsat = 20 kN/m3 γ = 17kN/m3 c = 0 ϕ = 280…

Q: Who are the active decision makers in terms of shaping how the built environment in urban centers…

A: It is asked about the active decision makers in terms of shaping how the built environment in urban…

Q: The RL of a point is 120 m and elevation of the instrument is 1 m. If a contour line of 119 m is to…

A: Given - RL of point = 120 m Elevation of the instrument (h) = 1 m Elevation of contour line from…

Q: Q-1: Water is flowing through a soil as shown in the figure. Determine the elevation, pressure, and…

Q: Example 5&6.1: Water flows from the faucet on the first floor of the building shown in figure E5&6.1…

A: Given, V1 = 20 ft/s To find : Flow velocity in basement and second floor faucet

Q: Design a bearing plate for ISMB 500@ 852.49 N/m resting on concrete support 250 mm thick for a…

Q: Given a cylindrical tank containing oil and water. The lower half is filled with water and the upper…

Q: Situation 3. Given the inclined force below: A 6 m B 5 C 3 Hinge 4 m 117 kN 4 65 kNm 6 m 7. What is…

Q: DETERMINE THE LENGTH OF AN EQUIVALENT PIPE OF DIAMETER 20 CM AND FRICTION FACTOR 0.02 FOR A GIVEN…

Q: 11. Find the total distance that a car travelled from the time the driver saw a hazard when he was…

Q: Prob-2: Determine the Moment Gradient factor, Cb, for EACH of the parts of the Beam shown below. L/3…

A: The moment modification can be calculated using the AISC code provisions. It is calculated for…

Q: Anaxial load Pis resolved into components A and B on an oblique plane as shown. Force is used in…

Q: Discuss the steps on how to delineate a watershed.

Q: A floor slab 100 mm thick is cast monollthically with beams 250 mm wide 450 mm deep spaced 1.2 m on…

A: Given:- The thickness of the slab = 100 mm The width of the beam = 250 mm The depth of the beam =…

Q: Draw the influence line of moment at point D. A Ain + Z २ B D + 1.5 fais t с

A: Length BD= 1.5 Length DC= 0.5 Length AB= 3

Q: xplain the need to preserve aseful solid materials in the environment for life

A: For resource conservation, economic stability, environmental protection, climate change mitigation,…

Q: A concrete dam of trapezoidal cross-section with one face vertical has a thickness of 3.5 m. at the…

A: Given, B=15 m H= 30 m μ=0.8

Question

Answer only 6.38

6.38 What is the source of fly ash? Why is fly ash sometimes added to concrete?
What are the different classes of fly ash?
6.39
A materials engineer is working in a research project to evaluate the effect of
one type of admixture on the compressive strength of concrete. She tested 10
mortar cubes made without admixture and 10 others with admixture after 28
days of curing. The compressive strengths of cubes without admixture were
25.1, 24.4, 25.8, 25.2, 23.9, 24.7, 24.3, 26.0, 23.8, and 24.6 MPa. The compres-
sive strengths of cubes with admixture were 25.3, 26.8, 26.5, 24.5, 27.2, 24.8,
24.1, 25.9, 25.3, and 25.0 MPa. Using the statistical t-test, does this admixture
show an increase in the compressive strength of the cement mortar at a level
of significance of 0.05?

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Step 3

VIEW

Step by step

Solved in 3 steps

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.

Similar questions

How does the addition of air-entraining materials to Portland cement improve the concrete?
Portland cement concrete consists of what four primary elements?
A1-What is the bond strength between steel and concrete and how it can be calculated? 2-What is the segregation of fresh concrete? Give its reason and how to control it? V3- What are the advantages of concrete? 3- Discuss the effect of age and curing on the compressive strength of concrete. 5-What are the main purposes of using plasticizer admixtures? 6-What are the main techniques that should be used to reduce heat of hydration in mass
A materials engineer is working in a research project to evaluate the effect of one type of admixture on the compressive strength of concrete. He tested eight mortar cubes made with admixture and eight others without admixture after 28 days of curing. The compressive strengths of cubes in psi with and without admixture are shown in Table P6.40.Using the statistical t-test, is there a significant difference between the meansof the compressive strengths of the two cement mortars at a level of signifi-cance of 0.10?
A materials engineer is working in a research project to evaluate the effect of one type of admixture on the compressive strength of concrete. He tested eight mortar cubes made with admixture and eight others without admixture after 28 days of curing. The compressive strengths of cubes in MPa with and without admixture are shown in Table P6.38. Using the statistical t-test, is there a significant difference between the means of the compressive strengths of the two cement mortars at a level of signifi- cance of 0.10?
The results of a laboratory experiment to evaluate the effects of a plasticizer are shown.a. Calculate the water/cement in each of the three cases. b. Choose an appropriate case that - by using water reducer, how can we increase the compressive strength of concrete without changing workability? (Refer to the appropriate case in the table) c. Choose an appropriate case that - by using a water reducer, how can we improve workability without changingthe compressive strength? (Refer to the appropriate case in the table)d. Choose an appropriate case that - by using water reducer, how can we reduce cost without changing workability or strength? (Refer to the appropriate case in the table)
A concrete masonry unit has actual gross dimensions of 7-5/8” * 7-5/8” * 7-5/8”. The unit istested in a compression machine with the following results:Max. Failure load = 83 kipsNet volume = 312.7 in3a) Is the unit categorized as solid or hollow? Why?b) Calculate the gross area compressive strength.c) Calculate the net area compressive strength.
what are the effects of aggregates in the performance of concrete?
What is the purpose of adding alcohol in test method C173? . When is it necessary to consolidate concrete by vibration in test method C231? Discuss the process of vibration when placing and consolidating the sample. When rodding a layer of concrete in method C138, is it okay to hit the bottom of the measure? If not, how is it supposed to be done?
Explain the effects of chemical and pozzolanic admixture on the fresh and hardened properties of concrete ? Help me
Explain why we need to use the smooth surface of the cubes for compressive strength testing. What would be the strength reading if you have used cylinders instead? 6. Discuss the correlation of UPV in terms of compressive strength anf concrete quality? 7. Discuss possible errors leading to unsatisfactory results. What are the modifications that might help to resolve these errors? 8. In your own words, explain your observations on how w/c, admixtures and puzzolans influenced the strength of concrete
A hollow concrete masonry unit has actual gross dimensions of 190 mm X190 mm X 390 mm (width X height X length). The unit is tested in a compression machine with the following results:Failure Load = 1110 kNNet volume of 6 X 106 mm3a. Calculate the gross area compressive strength.b. Calculate the net area compressive strength.