CEMENT ADDITIVE USE REDUCTION FACTORS TO IMPROVING THE QUALITY CONCRETE BIOCONC

Technology applications in the concrete mix is growing very rapidly in this modern era to obtain concrete results with characteristics that are environmentally friendly and non-toxic. Bioconc is innovation in developing green technology with the insertion of a micro-gap or slit gradation mycelia microbe as a micro-filter to mengoptimalkanatau reduce the amount of cement concrete on the concrete mix in total will increase the efficiency in the concrete and reduce the material components of the most expensive in the concrete, the cement. in job mix additive Bioconc require R%, ie a reduction factor of cement that will determine how the dose of cement and dose additive Bioconc, and therefore to seek R% require some percentage of reduction factor of cement optimum ranging from the concrete Normal, 5%, 10%, 15%, 20%, 25%, 30%, 35%.5 + 31271x4 4709x3 233.1x2 + 79.66x + 22:18, concrete quality obtained from normal concrete with fc '= 20 MPa generate optimum value reduction of cement amounted to 28.869%.


INTRODUCTION
Modern technology and sophisticated growing rapidly especially in the world of construction. One of the factors determining a structure in carrying static and dynamic loads, is the quality of materials pembentuknya.Beton is the most popular components used in the construction of building structures and many many experienced improvement in terms of strength, age, benefits and costs. It is known that the strength of concrete is heavily influenced by its constituent material composed of sand, stone aggregate, cement, water and other mixed materials. Improving the quality of the concrete mix will improve also the quality of concrete compressive strength. One way to improve the quality of the concrete mix is to use additional materials either synthetic or organic such as eg Bioconc. Bioconc is Bio-technology product is made from organic or natural materials, denatured proteins, biopolymers and mineral surfactant organic fermented by beneficial microbes. Bioconc is the performance of some microbes with dissolved nutrients, which will start working when, there is a supply of oxygen (aerobic process) and microbial performance ended when the concrete has reached the ultimate setting time, where there is no supply of oxygen again, and microbes in a state of dormant (sleeping). The microbial population growing exponentially over time.
Bioconc treat mixed concrete by inserting a space gap between fine aggregate and coarse aggregate were biyasanya filled Portland cement as a bonding agent, so that will reduce the amount of cement needed.

RESEARCH METHODS
Concrete is a mixture of portland or other hydraulic cement, fine aggregate, coarse aggregate and water, with or without additional mixed material forming a mass padat.Agregat -other aggregates are mixed together with a paste made of cement and water to form a time-like rock and tekadang using other mixed materials (admixture or additive). Material or material that is used among other things: 1. Cement The results from a combination of industrial raw materials limestone / lime as the main material and lempunung / clay or other substitute material with the final result of the solids in powder form (bulk). Definition of portland cement is a hydraulic cement produced by grinding slag portland cement mainly composed of calcium silicate which is hydraulic and ground together with other additives such as one or more of the crystalline form of compound calcium sulfate and may be combined with other additives. 2. Aggregate Aggregate is hard or stiff material concrete apartment blocks that percentage is most banyakmendominasi and can be derived from organic materials or inorganic. The volume of aggregate in the concrete occupy about 70% -75%, so the quality is very influence untun aggregate concrete quality. Aggregates are divided into two namely fine aggregate and coarse aggregate, wherein the block making agragat used is fine aggregate that passes 12 sieve with a diameter of 4.75 mm and retained on 0.063 mm sieve.

Water
The water used in the concrete mix should qualify C1602M ASTM standards. Mixing water used in prestressed concrete or concrete in which aluminum metal is embedded, including free water contained in the aggregate, may not contain chloride ions in the amount of harmful (SNI-25-BSN 2013). 4. Effect of Microbes Microbes are organisms that are small or micro. microbes can perform activities for life. Belonging to the prokaryotes such as bacteria, viruses, and eukaryotes such as algae, protozoa. Microbes play an important role in his life (Nester, Anderson, Robert, Nester, 2009). Microbes composed of bacteria, fungi, and viruses. In general, each microbe has morphological and anatomical structure of different (Waluyo, 2004). The primary role of microbes are decomposers of organic material. Besides harmful, microbes also has many benefits for humans and the environment. Microbes do not need a big place, easily grown in artificial media such as the presence of air and pembiakannya level relatively quickly. Therefore, each microbe has a role or influence in the life (Darkuni, 2001). Mikrobakteri used Bioconc enzyme, which is a product made from Bioconc organik.Enzim material is environment-friendly products, non-toxic, and safe for humans and other living creatures. Bioconc enzymes can also increase the compressive strength, reduce the weight of the cement, and reduce shrinkage cracks (Basoeki Makno, 2001). Microbes work "aerobic" and optimal work at room temperature 30 ° C, and will be dormant when in a room with a temperature of 60 ° C and above. Likewise, when are diruang without supply of oxygen, the microbes will be dormant or "sleep", as long as the packaging, before it is used. Shortly after these microbes are released (out of the packaging to be mixed into the concrete mix), then the microbes multiply rapidly and produce mycelia quickly to concrete, to fill the gap gradation which is usually filled with cement paste, so that the cement content is reduced. Along with the gap being filled mycelia gradation by microbes, the surface area increases tied to the cement paste (coupled with the microbe mycelia) which is correlated to the quality of concrete (concrete strength). When the concrete hydration process reaches a temperature of 60 ° C, the microbes will be dormant, and when the setting time of concrete has been achieved, and the supply of oxygen to the microbes have been isolated, the microbes will be dormant (Basoeki Makno, 2001). The characteristics of the microbes mycelia (Basoeki Makno, 2001): - The diameter of between 5μm s / d 10 μm -Length between 5μm s / d 30 μm -Growth speed sd 10,000,000 125,000,000 per day -Temperature survival for life is the temperature of the room s / d 60 ° C that occur in the process of setting concrete 1 hour (2 hours setting time of concrete with concrete transportation process assuming 1 hour, so stay 1 hour process. -Reduce heat -Menginsersi concrete gradation gap usually filled the cement paste. -Reduce shrinkage cracks, indicated the pattern of cracked concrete when done crushing concrete cube test as a comparison photo cube with treatment and without treatment.

RESEARCH RESULT
After laboratory tests on the materials used, made with standard concrete mix design according to ISO 7656-2012 in Table 1 below: The proportion of normal concrete mix above is also used to make by using different Bioconc with the required proportion of cement or cement-called reduction factor. Bioconcyang used are brand Bioconc of PT. Bangun Mukti Abadi. As for job-mix calculation using Bioconc by the formula. Coarse Aggregates C C + ((A + B) * R% * (C / (C + E))) 4 Fine aggregate D D + ((A + B) * R% * (E / (C + E))) 5 Bioconc -500 TOTAL WEIGHT A + B + C + D + 500cc Here is the composition of the normal plan per m3 of concrete constituent material used   The statistical analysis used seek optimum levels of cement reduction factor for compressive strength of concrete is the rank of polynomial regression analysis. In this study, the variable (x) is a free variation reduction factor of cement and the dependent variable (y) is the compressive strength of concrete. Rank regression analysis are presented in the following figure: