@article{Hiroshi Kubo_Shinya Inazumi_Toshihiko Miura_2018, title={HYDROCHLORIC ACID HEAT REACTION METHOD TO MEASURE CEMENT CONTENTS IN CEMENT MIXED SOILS}, volume={15}, url={https://geomatejournal.com/geomate/article/view/789}, abstractNote={<p>The mixing cement with soft soil to increase their strength has been used in many construction<br>sites and it is important that soil and cement are well mixed. In order to evaluate the mixing accuracy during<br>construction, it may be required to measure the cement content by sampling the cement mixed soil. While there<br>are several methods for measuring cement content, the hydrochloric acid heat reaction (HAHR) method is<br>easiest and quickest and is relatively high in precision to measure the cement content in fresh concrete.<br>However, to apply HAHR to the fresh soil cement, there were many questions about a test condition. This<br>study investigated conditions to apply the HAHR method to cement mixed soil. At first, cement are mixed to<br>the local soil samples in the ratio of 0 to 10g/100g. Initial temperatures (T0) of the mixed soil and hydrochloric<br>acid are measured. 100 g of mixed soil is put in an insulated container. 100mL of hydrochloric acid is added,<br>and reaction temperature (T1) is measured. Relationship of temperature rise (T1-T0) and cement content is a<br>calibration graph. The relation is proportional. And, the temperature rises are measured about 100g of cement<br>mixed soil of the site. Its cement content is obtained using the calibration curve. It is optimal to use 6M<br>hydrochloric acid for this method. It is necessary to examine it with local soil and local cement to prepare a<br>calibration curve. When the water content ratio of the soil greatly changes, it is necessary for the calibration<br>curve to be updated. HAHR tests are done in 10 to 60 minutes after having mixed soil and cement in the case<br>of samples containing a little water. But, in the case of containing much water, the tests are done under the<br>specified elapsed time. As an example of the result, the cement content of soil can be determined from the<br>rising temperature of the sample soil.<br><br></p>}, number={52}, journal={GEOMATE Journal}, author={Hiroshi Kubo and Shinya Inazumi and Toshihiko Miura}, year={2018}, month={Oct.}, pages={177–183} }