MONITORING OF CURING TEMPERATURE OF CONCRETE
Using a simulator / indicator and a set of thermocouple wires embedded at the concrete core, CTC monitors temperature at different setpoints within the concrete block every hour for 7 days. Ambient temperature is also measured. Temperature profile derived from monitoring during mock trials serve to guide concrete designers on the acceptability of the mix design. Monitoring of in-situ concrete, on the one hand, facilitates the dependability and quality control of the mixture.
SAMPLING/SAMPLE PREPARATION
At the request of the customer, CTC conducts sampling of cement and raw materials on site. Sampling is done following PNS ASTM C183 and the CTC sampling procedure. Sampling personnel are trained to collect samples from bulk storage at points of discharge, from conveyors, bodega and trucks, as well as packaged cement from construction supply stores.
Upon arrival/receipt in the laboratory, a homogenous sample is prepared as representative for testing and retention. Samples are stored in suitable containers, sealed and marked, and then endorsed to the testing group when withdrawn for testing.
REFERENCE MATERIAL PRODUCTION
During the 6 rounds of CeMAP Proficiency Testing Program (from 2012 to 2019), CTC was tasked to produce the cement reference materials. The CeMAP PT Program was participated by CeMAP member companies, other private cement testing laboratories and DPWH laboratories. Participation to the CeMAP PT Program is a requirement of DPWH for their accredited laboratories following the Department Order no. 45 in 2012. Cement sample is homogenized using a one-ton mechanical mixer, and then packaged for chemical analysis (about 100grams) and physical/mechanical analysis (about 5kg).
CALIBRATION & MAINTENANCE
All equipment and materials used by CTC from preparation to sample testing are calibrated and maintained following the annual calibration and preventive maintenance schedule. CTC passed the measurement audit in years 2015, 2016 and 2020 for timer, analytical balance and volumetric glasswares, and in year 2020 for furnace. These measurement audits were done by National Metrology Laboratory (2015 and 2016) and by another PAB accredited laboratory (2020). The reference standards used by CTC for in-house calibration, as well as other equipment such as Universal Testing Machine (for CS test), Le Chatelier flasks and pressure gauges are externally calibrated by PAB accredited laboratories for ISO/IEC 17025. To ensure compliance of equipment and materials, there is a schedule of specifications checking done internally.