COMPRESSIVE MORTAR STRENGTH.docx

**COMPRESSIVE MORTAR STRENGTH** - For cement testing, the required room temperature is ranging from 20°C - 27°C. - For moist cabinet, the humidity is 50. **PHYSICAL TEST** -- sieve no. 20 passing retained on sieve no. 30 **CHEMICAL TEST** -- sieve no. 100 passing **3-gang mold** - cu...

**COMPRESSIVE MORTAR STRENGTH** - For cement testing, the required room temperature is ranging from 20°C - 27°C. - For moist cabinet, the humidity is 50. **PHYSICAL TEST** -- sieve no. 20 passing retained on sieve no. 30 **CHEMICAL TEST** -- sieve no. 100 passing **3-gang mold** - cube size is 2in by 2in - It is the place where the passing measured cement mix on flow table is being molded. **TEST REQUIREMENTS AND EQUIPMENTS USED** Equipment Used: - Graduated Cylinder - Wash Bottle - Rubber Tamper *(Size ½ in x ½ in x 150mm)* - Timer - Conical mold **(4 in)** *(For Type 1p and 1t)* - Flow Table *(For Type 1p and 1t)* **FOR 2 MOLDS** - 500 g of cement - 1375 g Ottawa Sand - 242 ml water *(For Type 1p and 1t)* **FOR 3 MOLDS** - 740 g of cement - 2035 g Ottawa Sand - 359 ml water *(For Type 1p and 1t)* [**110** **±** **5%**]{.math.inline} **-** flow table for types 1p and 1t - The sample must be placed in the **conical mold** in two layers wherein each layer must be pressed with a **rubber tamper** in 20 blows. - Perform a 1-minute standby and remove the conical cone. - Perform 25 blows on flow table in 15 seconds. - Measure the cement in the flow table if it passes or fails. - If passed put the cement samples in the 3 gang mold, if it fails repeat the process. **CEMENT MIXER/MORTAR MIXER** **Slow Speed** - [140 ± 5 *rpm*]{.math.inline} **Medium Speed -** [285 ± 10 *rpm*]{.math.inline} **STEPS** 1\. Put the water into the bowl. 2\. Then put cement. 3\. Put the mixed sample into the machine for 30 seconds under slow speed together with the Ottawa sand. 4\. 30 seconds for medium 5\. 90 seconds standby while scraping it for 15 seconds. 6\. 1 minute medium speed for final mix. **Note:** For type 1, no need to undergo flow table. Only type 1p and 1t undergo flow table. 7\. After the final mix, put the sample on the conical mold at the top of the flow table and perform 20 blows per layer for 2 layers. 8\. After step 7, let the sample standby for 1 minute in the conical mold and remove it after. 9\. Perform 25 blows in 15 seconds in the flow table. 10\. If the sample passes the required measurement proceed with step 11 however if it fails, redo the entire process. 11\. After the flow table perform a 15-second medium speed. 12\. Fill all the molds before tampering wherein each cube needs to have 32 tamps. 14\. Within 2 minutes the tampering must be finished. - The required temperature for the moist cabinet and water bath for cement curing must be [**23** **±** **1.7**^**∘**^**C**]{.math.inline}**.** - The sample that have been put on the **3 gang mold** will be put on the moist cabinet for **24 hours**. - After that, the sample will be submerged in the water bath in the increments of 3, 7, and 28 days. **REQUIRED STRENGTH FOR CEMENT MORTAR WITH RESPECT TO DAYS SUBMERGED AND TYPE OF CEMENT USED** **TYPE I** 12 Mpa -- 3 days 19 Mpa -- 7 days **Note:** The sample must attain a strength on the 7^th^ day at least 85% of the strength required on the 28^th^ day. Otherwise, continue waiting until 28 days. 28 Mpa -- 28 days **TYPE IP & 1T** 13 Mpa -- 3 days 20 Mpa -- 7 days 25 Mpa -- 28 days **TOLERANCE** 3 days -- 1 hr tolerance 7 days -- 3 hrs tolerance 28 days -- 12 hrs tolerance **TYPES OF CEMENT** **TYPE IP** -- Blended Cement (*Portland Pozzolan)*: Plastering **TYPE IL** -- Blended Cement (*Portland Limestone)* **TYPE IT** -- Blended Cement (*Portland Volcanic Tuff)* **PORTLAND TERNARY** *(Ex: Portland, Pozzolan, Fly Ash)* **TYPE I -- *Portland Cement --*** For general use construction **SPECIFIC GRAVITY OF CEMENT** **MATERIALS NEEDED:** - Le Chatelier Flask - Funnel - Porcelain Dish - Double Ended Spatula - Kerosene - 64g cement **STEPS:** 1\. Prepare the Le Chatelier Flask and fill it with kerosene just between 0-1. 2\. Afterwards prepare a water which is [25℃]{.math.inline} and submerge the flask for 5 minutes. 3\. Weigh the flask with kerosene 4\. Put the cement sample on the flask until the air bubbles comes out. 5\. Submerge it water for 30 minutes. **FINESS MODULE** **TEST REQUIREMENTS** - The ideal weight of the cylindrical measure must be less than 900g. - For type I cement, the sample must pass sieve no. 200. - For type IP and IT cement, the sample must pass sieve no. 325. **STEPS** 1\. Prepare 50g cement sample for type I and 100g for type IP and IT. 2\. Perform 4 minutes sieving. 3\. Perform 9 minutes sieving. For blended cement, perform wet sieving and the maximum sample retained on sieve no. 325 must 20%. **NORMAL CONSISTENCY** - To know the water needed to achieve normal consistency. **MATERIALS/EQUIPMENTS NEEDED:** - Vicat Apparatus - Plunger **10mm** for **normal consistency** - Neddle **1mm** diameter for **time setting** - Conical ring - Glass Plate - The required penetration must be [10 ± 1 *mm*]{.math.inline} penetration within 30 seconds. **Autoclave -** machine high pressurized high heat **Autoclave Specimen** - 0.8% allowable expansion of cement - 0.2% allowable shrinkage in the length comparator **Magnesium Oxide** -- causes the expansion of cement **Autoclave Molds** **STEPS:** 1. 650g cement, true to all types of cement covered all (time setting, initial set, final set) 2. Use distilled water for normal consistency. 3. 160ml trial for water. 4. Put the cement. 5. 30 seconds absorption time standby 6. Slow speed for 30 seconds 7. After that stop the machine 8. 15 seconds scraping 9. Medium speed for 1 minute 10. Mold the cement into balls 11. Throw 6 in apart 6 times 12. Put the cement ball to conical ring 13. Mold into conical ring 14. Put the sample into vicat apparatus use plunger for normal consistency 15. The reading must be [10 ± 1*mm*]{.math.inline} 16. If fails, redo the process and try to adjust the water content 17. If passed, put the sample into autoclave molds 18. Put oil into the mold before putting the sample 19. Press the sample using thumb. **For Time Setting** 1\. Position of needle must be 10mm from center and from sides. 2\. The time of setting is performed 45 minutes from Normal Consistency. 3\. Then 15 minutes interval. 4\. 25 mm penetration must be achieved 5\. Linear interpolation is used to predict the time where the 25 mm is achieved 6\. Leave the Specimen, maintain for 3hrs 215 degrees. 295 psi