Update from Rodriguez Engineering on the sulfates issue … I was advised that the contractor will probably go ahead and proceed with liming tomorrow.

 

Regards,

 

Joel

 

 

Joel Jenkinson

Director, Addison Airport

  main: (972) 392-4850

  fax: (972) 788-9334

________________________________

From: McIllwain, Frank O. [mailto:FOMcIllwain@GarverUSA.com] 
Sent: Thursday, April 21, 2011 4:53 PM
To: Bobby McClelland
Cc: Matt Aquino; Harry Lorton; Wayne Staudenmaier; McAnally, Mitchell, R; Jenkinson, Joel
Subject: FW: Addison Airport

 

Bobby,

 

Here are the results and recommendations from additional testing. Please proceed per Rodriguez’s recommendations and in conformance with the specifications.

 

Frank McIllwain, PE
Garver
972-377-7480

 

From: RodriguezLab@aol.com [mailto:RodriguezLab@aol.com] 
Sent: Thursday, April 21, 2011 4:42 PM
To: McIllwain, Frank O.
Cc: bgm@easlp.com; Tolmachoff, J, Derek.; harry.lorton@txdot.gov; mpa@easlp.com; M.mcanally@garverusa.com; rprservices@gmail.com
Subject: Addison Airport

 

Frank,

Upon reviewing the sulfate test results (attached report RE11 0750) for Addison airport, it appears that the soil that has been brought in by the contractor has a moderately high sulfate
content.  The highest value tested is in a blended sample and is 2800 ppm (0.28 percent). 

To reduce the sulfate concentration the soil needs to be processed by milling, blading, mixing or other method such as to dilute the sulfate concentration in the soil with other soil.


The process of adding lime will greatly aid in accomplishing this process.  If the contractor would like to add the lime and perform the initial mixing, the mellowed soil will be easier
to process.  Due to the higher sulfate content, the mellowing period should be extended to min. 4 days, preferred 6 days. Then final mixing should occur, followed by additional blading.

A visual inspection and additional sampling for sulfate testing shall be performed before and after compaction on the treated material to reduce the risk to the project. 

P. S. Please note: Attached is RE11 0721 Supplemental Report that includes the additional Soluble Sulfate Content of samples before the mixing of materials.

 

Thank you,

Oscar H. Rodriguez, P. E.

Rodriguez Engineering Laboratories

512-251-4454

________________________________

This e-mail and any attachments contain URS Corporation confidential information that may be proprietary or privileged. If you receive this message in error or are not the intended recipient,
you should not retain, distribute, disclose or use any of this information and you should destroy the e-mail and any attachments or copies.