standard test method for length change of hydraulic cement mortars exposed to a sulfate solution

Designation: C 1012 – 034

GROUP MEMBERS;

SAFIULLAH(13ce07)

NASIR ALI(13ce32)

SECTION; A

SUBMITTED TO; ENGG SOHAIL SALEH

DEPARTMENT; CIVIL

Sequence of Presentation Scope

Significance and Use

Apparatus

Reagents and Materials

Procedure

Calculation

Report

Keywords

This test method covers the determination of length change of mortar bars immersed in a sulfate solution.

The values stated in SI units are to be regarded as the standard.

This standard does not purport to address all of the safety concerns, if any, associated with its use.

Scope

Significance and Use

This test method provides a means of assessing the sulfate resistance of mortars and blended hydraulic cements.

The standard exposure solution used in this test method, may be used to simulate the environmental exposure of interest.

Apparatus

(a)

(b)

(c)

(d)(f)

Mixer. (a)

Cube Molds, (b)

Bar Molds. (c)

Comparator, (d)

Containers, (e)

Curing Tank, (f)

4. Reagents and Materials

USP or technical grade chemicals may be used.

Sodium Sulfate (Na2SO 4)

Sulfate Solution

Graded Standard Sand.

Stainless Steel Gage Studs .

Procedure

Molding and Initial Curing of Specimens—Mold the test bars and the cubes in accordance with Test. A set of specimens to test one cement consists of 6 bars and up to 21 cubes .after molding, cover the molds, and place the mold in the curing tank in water at 35 6 3°C for 23 h 30 min. Place the sealed molds in the curing tank. remove molds from tank and demold the specimens.

Subsequent Curing and Preparation for Test; store all bars in a curing tank of saturated limewater.Break two cubes if the mean strength is 2850 psi or

more place all the bars in the sulfate solution.If it is less than 2850 psi store all the demold cubes and

bars in the curing tank and test additional cubesWhen reach to 2850 psi record comparator readings and

place all the bars in the sulfate solution

Measurements of Length Change: At 1, 2, 3, 4, 8, 13, and 15 weeks after the bars are placed in the

sulfate solution, test them for length change. Review the data at 15 weeks. If uniform length change is taking place, make the next subsequent measurements at a minimum of 4, 6, 9, and 12 months. When the expansion is changing rapidlybmeasure the bars at 4, 6, 9, 12, 15, and 18 months

Calculation 10.1 Calculate the length change at any age as follows:

DL=[(Lx – Li)/Lg] 100 where:DL = change in length at x age, %, L x = comparator reading of specimen at x ageL i = initial comparator reading of specimen-reference bar comparator reading, at the same time Lg = nominal gage length, or 250 mm (10 in.) as applicable.

Calculate length change values for each bar to the nearest 0.001 % and report averages to the nearest 0.01 %.

Report Report type of cement, and, if blending material is used,

its identification and amount and whether cement and blending material, if used, meet the applicable specifications. Report the initial comparator reading of each bar at the time of immersion in sulfate solution; this is the base value for calculation of length changes. Report the subsequent length changes in percent of base value to the nearest 0.001 % for individual bars and the nearest 0.01 % for averages.

Keywords

acceptability; expansion; fly ash; mortars; pozzolans; precision; search report; slag; sulfate attack; sulfate-resisting cements; tests