Journal of Civil Engineering Science & Technology Vol. 03/No. 02/ October 2022 96 Comparative Analysis of The Cost of Conventional and Precast Concrete Slabs on High-Rise Building Projects Diah Kurniawati Ningtyas 1 , Aprilia Regita Tri Cahyani 1 , Zetta Rasullia Kamandang 1* , Muh. Darul Muttaqin 1 , Rizky Nur Cahyanto 1 1 Civil Engineering Study Program, University of Pembangunan Nasional "Veteran" East Java *Corresponding author: zerasullia.ts@upnjatim.ac.id INTRODUCTION Construction technology has developed rapidly in terms of equipment, materials, and methods used. With the increasingly rapid technological advances in the construction field, the innovation that has emerged is the floor slab system using precast which is another alternative to the conventional slab method [1]. One of the main processes in carrying out a construction project is knowing how much funds should be provided for a building. In carrying out these activities, one must understand the construction process as a whole, both the type of work, the need for tools, as well as the price of materials and wages; this is to obtain precise and efficient calculations [2]. The slab is a thin structure made of reinforced concrete with a plane perpendicular to the structure’s plane [3]. While the definition of the floor slab is the level of the barrier between the lower floor and the floor above. In its manufacture, the floor slab is supported by beams that rest on the building's columns. Floor slabs must be sturdy and rigid, have the same height, and be comfortable to stand on [4]. Precast Concrete is concrete that is molded in several locations (both in the project environment and in factories) and is finally installed in a position with a connection system so that the series of precast concrete elements into a unified whole as a structure (Precast Concrete) Plant Cast Precast and Prestressed) (Guide Data for Implementation Methods of PT PP (BDE/GDG/STR/PLT/2015/005)) [5]. Concrete slabs can be manufactured with several alternatives, including conventional and precast methods. Many high-rise building construction works use the full slab precast method for floor slab work. Conventional and precast methods have their respective advantages and disadvantages. Therefore, this study was conducted with the aim of comparing the most effective and economical methods to minimize production costs on the floor slab construction of an eight-story building with a land area of 3,500 m 2 and a building area of 1,700 m 2 . RESEARCH METHODS 2.1 Method of collecting data The collection of data is taken from the literature and the calculation of the Budget Plan (RAB) which refers to the implementation of the construction of an eight-story building in Malang City. The flow of the implementation of the conventional plate and precast full slab work methods is shown in Figure 1. 2.2 Implementation Method 1. Conventional Method The implementation of the conventional method is carried out by installing iron and formwork and then moving the liquid or ready-mix concrete from the mixer truck into it [6]. The use of ready mix is done to reduce the risks that can arise due to the concrete not being under the expected specifications. In addition, to avoid the accumulation of concrete materials (cement, sand, and gravel) at the project site [7]. Or concrete that is cast in place, with molds or references installed at the location of structural elements in buildings or buildings Abstract Construction processes, particularly floor slab systems, can be executed using precast/precast methods as technology advances. Compared to traditional methods, which need more time and production expenses, precast/precast methods are more cost-effective for floor slab formwork, neater, and have a more consistent finish. This study is based on an eight-floor building project with 92 residential units on a 3,500 m 2 plot of land and a 1,700 m 2 building size. This investigation used two technologies: conventional precast slab and full slab precast. The purpose of this research is to compare the most cost-effective strategy for reducing production costs on floor slab work for the construction of the case study. Based on the calculation results, the full slab precast method is 14.31% or around Rp. 980,508,000 is more economical than the conventional method. For the conventional method, the total cost is Rp. 3,914,657,000 while for the precast method, the result is Rp. 2,934,149,000. Keywords: conventional precast, cost comparison, economical, full slab precast Article Info Received 26 October 2022 Revised 03 November 2022 Accepted 03 November 2022