Tujuan penelitian ini adalah untuk mengetahui (1) Pengaruh penggunaan abu vulkanik sebagai pengganti sebagian agregat halus terhadap kuat tekan dan berat jenis beton, (2) kuat tekan optimal beton, (3) berat jenis optimal beton. (4) bahan ajar yang didapatkan pada mata kuliah teknologi beton tentang pengaruh abu vulkanik pada kuat tekan dan berat jenis pada beton normal.  
Penelitian menggunakan metode kuantitatif eksperimen dan teknik analisa menggunakan analisis regresi. Variabel yang mempengaruhi dalam penelitian adalah (1) variabel terikat: kuat tekan beton dan berat jenis beton, (2) variabel bebas: variasi 0%, 10%, 15%, 20%, dan 25% kebutuhan abu vulkanik dari total berat pasir. Benda uji yang digunakan berupa silinder dengan diameter 150 mm dan tinggi 300 mm.
Berdasarkan hasil penelitian disimpulkan bahwa, (1) variasi abu vulkanik sebagai pengganti sebagian agregat halus berpengaruh kuat terhadap kuat tekan dan berat jenis beton, (2) nilai optimal kuat tekan dan berat jenis beton masingmasing yaitu pada variasi abu vulkanik 8,36% sebesar 23,231 MPa, 11,889% sebesar 22,919 MPa, (3) nilai campuran beton yang optimal secara keseluruhan yaitu pada variasi abu vulkanik 11,889%, (4) bahan ajar yang berupa suplemen bahan ajar tentang pemanfaatan abu vulkanik gunung Kelud sebagai pengganti sebagian agregat halus pada beton ditinjau dari kuat tekan dan berat jenis.

Kata kunci: beton normal, abu vulkanik, kuat tekan, berat jenis

The purpose of this study was to determine (1) Effect of volcanic ash in partial replacement of the total fine aggregate of compressive strength and the density of the concrete, (2) resistance to the optimal compression of the concrete (3) optimum density concrete. (4) The teaching material obtained in the course of concrete technology on the effect of volcanic ash on the compressive strength of concrete and normal density.
Experimental studies using methods and analytical techniques using a quantitative analysis of regression. Variables in the study were (1) the dependent variable: the strength of concrete in compression and the density of concrete, (2) independent variables: the variation of 0%, 10%, 15%, 20% and 25% Volcanic ash from the total weight of the sand. The sampel is  in the form of a cylinder with a diameter of 150 mm and a height of 300 mm.
Based on the results of the study concluded that (1) changes in volcanic ash as a partial replacement of the fine aggregate strong overall influence on the compressive strength and density of concrete, (2) the optimal value of compressive strength and the weight of each type of concrete which is the variation of volcanic ash 8,36% amounted to 23,231 MPa, 11,889% to 22,919 MPa, (3) the value of the optimal concrete mixture as a whole, to namely the variation of volcanic ash 11,889% (4) in the form of teaching material to supplement teaching materials using Kelud volcanic ash as a partial replacement of fine aggregate on in terms of compressive strength concrete and density.

Key words: normal concrete, volcanic ash, compressive strength, density.