This research aimed to identify techniques to control pH levels during in-stream construction projects involving grout paving of culverts. The researcher tested different flow rates and organic materials to determine methods to keep pH within Maryland's standard of 6.5-8.5. Faster flow rates resulted in lower pH levels. Certain organic materials like peat also decreased pH over time. Future work includes exploring optimal placement of sediment bags containing organic mixtures and adding carbon dioxide to the water. The goal is to provide guidance to the State Highway Administration on maintaining culverts in compliance with water quality regulations.

1. Identification of Techniques to Meet pH
Standards During In-stream Construction
Principal Investigators
Jalil Abdul
Mentor
James G. Hunter, Ph.D.
Morgan State University
Department of Civil Engineering

2. Overview
• Purpose for Research
• Objectives
• Background
• Methodology
• Results
• Conclusions
• Acknowledgements

3. Purpose for Research
 The main purpose of this research is to provide
guidance to State Highway Administration (SHA)
for routine maintenance of culverts requiring grout
paving and to assist SHA in meeting Maryland's
water quality standard for pH.

4. Research Objective
 Understand the issues, materials, and methods for
field projects dealing with in-stream maintenance
of highway culverts.
 To meet the new Maryland Standard regulation for
pH between 6.5-8.5 for construction sites, most
importantly culverts.

5. Background
What is a Culvert ??
A culvert is a conduit used to
convey water from one area to
another, usually from one side of a
road to the other side.
Culverts are generally
constructed out of concrete,
galvanized steel, aluminum, or PVC.

6. Background
• Culverts fail when the materials they are made weaken or deteriorate from
corrosion.
• Soil and sand carried through a culvert can wear away the galvanizing of a
steel culvert, allowing it to corrode and eventually collapse, disrupting the
road or railway above it.
• Failure can also occur from erosion of the soil around or under the culvert.

7. Background
• If the failure is sudden and catastrophic, it can result in injury or loss of life.
• The risk for culvert failure is even greater when the culvert is poorly designed or
undersized. Water passing through undersized culverts will scour away the
surrounding soil over time.
• This is why inspection, maintenance, and replacement of these structures is crucial
for good infrastructure and safety.

8. Concern with Using Grout Paving to Maintain Culverts
• Grout is essentially Portland Cement / Sand / Water
• Grout is combination of cement and lime (CaO)
• When cured grout and water interact, the water pH can
rise as high as pH 10 – 11 in the field.
• Maryland regulatory limit for pH is 6.5 – 8.5
• High pH is a concern for potential ecological impacts
• High pH can cause other chemicals in the water to
become more toxic.

9. Methodology
To control the pH level by:
1. using different of Flow Rates
2. using different types of Organic Materials.

10. Methodology
Different of Flow Rates
 Basic Flow Rate 900 ml/minutes
 High Flow Rate 1800 ml/minutes
 Big Wash 900 ml/minutes
 Highest Flow Rate 3600 ml/minutes
 Tropical Treatment 900 ml/minutes

11. Constructing New Culvert
 Grouting Mixing Ration
13 kg Cement
13 kg Sand
6.5 kg Water
 Mixed two batches of Grout to make four culverts.
 The Grout dried in two days.

12. Runoff New Grout Surface
Checking pH

13. Big Wash Experiment
 In this experiment the water overflows the end of the culvert.
 Testing
pH, Total dissolved solids (TDS), and Conductivity (CON)

14. Tropical Treatment Experiment
 Painted culvert white (two coats) after Grout dried one day.
 Conducted the Basic Flow rate (900 ml) Experiment.

15. Designing Sediment Bag Experiment

16. Organic Material Experiment
 Used the Sediment Bag
 Used different type of Organic Materials to decrease the pH.

17. Testing Organic Materials
Organic Materials Used (4 inches)
• Hay
• Peat
• Pine Mulch
• Hardwood Mulch

18. Collecting Sample and
Using Different Flow Rate
1 gallon/minute 2 gallon/ minute
* Collecting samples after time intervals
0, 3, 10, 30, 60, 100 minutes

19. Analyzing Organic Materials
 Testing
Nitrogen
Phosphorus
Alkalinity

20. Flow Rate Results
High Flow Rate 1800 ml/min Fast Flow Rate 3600 ml/min
4
6
8
10
0 6 12 18 24
pH
time(hr)
4
6
8
10
0 2 4 6
pH
time(hr)

21. Organic Materials Results
Hay Result Peat Result
4
6
8
10
0 2 4 6
pH
time(hr)
4
6
8
10
12
0.0 0.5 1.0 1.5 2.0
pH
time(hr)

22. Conclusions
 In our experiment we observe that faster flow
rate resulted in lower pH levels.
 Certain Organic Materials can decrease the pH
level.
 Tropical Treatment and Big Wash Experiments
did not decrease the pH level.

23. Future Plan
Add CO2

24. Future Plan
Finding the Best Location For The Sediment Bags

25. Future Plan
Using Different Ratios of Organic Materials.
Combination
Mixing Peat & Hay
Mixing Peat & Pine Mulch
Mixing Hay & Pine Mulch

26. Acknowledgement
• Maryland State Highway Administration
• MUS National Transportation Center
• Dr. James Hunter
• Dr. Dong Hee Kang
• Dr. John Wheatland
• Dr. Masud Salimian
• SEM Summer Research Program
• My Research Team

27. Thank you
Questions?
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