Marthen M. Tangkeallo, Lawalenna Samang, Achmad Bakri Muhiddin, A.R. Djamaluddin, Experimental Study on Bearing Capacity of Laterite Soil Stabilization using Zeolite Activated by Waterglass and Geogrid Reinforcement as Base Layer, Journal of Engineering and Applied Sciences, Volume 15,Issue 6, 2020, Pages 1496-1501, ISSN 1816-949x, jeasci.2020.1496.1501, (https://makhillpublications.co/view-article.php?doi=jeasci.2020.1496.1501) Abstract: Indonesia is a country with a large amount of laterite soil and zeolite which could be found in an abundant amount in North Toraja. Zeolite is widely used for industrial purposes. Its pozzolanic behavior could also be used as soil stabilizing material. In this research, laterite soil was stabilized using varied refined zeolite percentage of 4, 8, 12, 16 and 20% activated by using waterglass with 2, 4 and 6% of soildry weight which then applied in road foundation layer model. California bearing ratio test results of the mixture increased significantly. CBR value increases corresponding with increasing zeolite and waterglass percentage and with increasing curing time. The highest CBR value obtained was 70.44% achieved by adding 20% zeolite and 6% waterglass with 28 days of curing time. Compared to the untreated soil CBR value of 18.70%, the CBR value increased by 376%. As in the model test, the value of modulus of subgrade reaction of stabilized laterite soil was 636.94 kNm–2 per mm and by using geogrid as reinforcement, it increased by 150% and reach a value of 955.41 kNm–2 per mm. This result showed that laterite soil stabilization using zeolite activated by waterglass could be properly used as a road foundation. Keywords: California Bearing Ratio (CBR);laterite soil;base layer;subgrade;waterglass